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minix/kernel/system/do_vmctl.c

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Basic VM and other minor improvements. Not complete, probably not fully debugged or optimized.
2008-11-19 13:26:10 +01:00
/* The kernel call implemented in this file:
* m_type: SYS_VMCTL
*
* The parameters for this kernel call are:
* SVMCTL_WHO which process
* SVMCTL_PARAM set this setting (VMCTL_*)
* SVMCTL_VALUE to this value
*/
#include "../system.h"
#include "../vm.h"
#include "../debug.h"
re-establish kernel assert()s. use the regular <assert.h> assert() instead of vmassert() in kernel. throw out some #if 0 code. fix a few assert() conditions. enable by default.
2010-03-10 14:00:05 +01:00
#include <assert.h>
Basic VM and other minor improvements. Not complete, probably not fully debugged or optimized.
2008-11-19 13:26:10 +01:00
#include <minix/type.h>
/*===========================================================================*
* do_vmctl *
*===========================================================================*/
This patch removes the global variables who_p and who_e from the kernel (sys task). The main reason is that these would have to become cpu local variables on SMP. Once the system task is not a task but a genuine part of the kernel there is even less reason to have these extra variables as proc_ptr will already contain all neccessary information. In addition converting who_e to the process pointer and back again all the time will be avoided. Although proc_ptr will contain all important information, accessing it as a cpu local variable will be fairly expensive, hence the value would be assigned to some on stack local variable. Therefore it is better to add the 'caller' argument to the syscall handlers to pass the value on stack anyway. It also clearly denotes on who's behalf is the syscall being executed. This patch also ANSIfies the syscall function headers. Last but not least, it also fixes a potential bug in virtual_copy_f() in case the check is disabled. So far the function in case of a failure could possible reuse an old who_p in case this function had not been called from the system task. virtual_copy_f() takes the caller as a parameter too. In case the checking is disabled, the caller must be NULL and non NULL if it is enabled as we must be able to suspend the caller.
2010-02-03 10:04:48 +01:00
PUBLIC int do_vmctl(struct proc * caller, message * m_ptr)
Basic VM and other minor improvements. Not complete, probably not fully debugged or optimized.
2008-11-19 13:26:10 +01:00
{
Removed unused symbols. Minor cleanups.
2010-01-22 23:01:08 +01:00
int proc_nr;
Basic VM and other minor improvements. Not complete, probably not fully debugged or optimized.
2008-11-19 13:26:10 +01:00
endpoint_t ep = m_ptr->SVMCTL_WHO;
Primary goal for these changes is: - no longer have kernel have its own page table that is loaded on every kernel entry (trap, interrupt, exception). the primary purpose is to reduce the number of required reloads. Result: - kernel can only access memory of process that was running when kernel was entered - kernel must be mapped into every process page table, so traps to kernel keep working Problem: - kernel must often access memory of arbitrary processes (e.g. send arbitrary processes messages); this can't happen directly any more; usually because that process' page table isn't loaded at all, sometimes because that memory isn't mapped in at all, sometimes because it isn't mapped in read-write. So: - kernel must be able to map in memory of any process, in its own address space. Implementation: - VM and kernel share a range of memory in which addresses of all page tables of all processes are available. This has two purposes: . Kernel has to know what data to copy in order to map in a range . Kernel has to know where to write the data in order to map it in That last point is because kernel has to write in the currently loaded page table. - Processes and kernel are separated through segments; kernel segments haven't changed. - The kernel keeps the process whose page table is currently loaded in 'ptproc.' - If it wants to map in a range of memory, it writes the value of the page directory entry for that range into the page directory entry in the currently loaded map. There is a slot reserved for such purposes. The kernel can then access this memory directly. - In order to do this, its segment has been increased (and the segments of processes start where it ends). - In the pagefault handler, detect if the kernel is doing 'trappable' memory access (i.e. a pagefault isn't a fatal error) and if so, - set the saved instruction pointer to phys_copy_fault, breaking out of phys_copy - set the saved eax register to the address of the page fault, both for sanity checking and for checking in which of the two ranges that phys_copy was called with the fault occured - Some boot-time processes do not have their own page table, and are mapped in with the kernel, and separated with segments. The kernel detects this using HASPT. If such a process has to be scheduled, any page table will work and no page table switch is done. Major changes in kernel are - When accessing user processes memory, kernel no longer explicitly checks before it does so if that memory is OK. It simply makes the mapping (if necessary), tries to do the operation, and traps the pagefault if that memory isn't present; if that happens, the copy function returns EFAULT. So all of the CHECKRANGE_OR_SUSPEND macros are gone. - Kernel no longer has to copy/read and parse page tables. - A message copying optimisation: when messages are copied, and the recipient isn't mapped in, they are copied into a buffer in the kernel. This is done in QueueMess. The next time the recipient is scheduled, this message is copied into its memory. This happens in schedcheck(). This eliminates the mapping/copying step for messages, and makes it easier to deliver messages. This eliminates soft_notify. - Kernel no longer creates a page table at all, so the vm_setbuf and pagetable writing in memory.c is gone. Minor changes in kernel are - ipc_stats thrown out, wasn't used - misc flags all renamed to MF_* - NOREC_* macros to enter and leave functions that should not be called recursively; just sanity checks really - code to fully decode segment selectors and descriptors to print on exceptions - lots of vmassert()s added, only executed if DEBUG_VMASSERT is 1
2009-09-21 16:31:52 +02:00
struct proc *p, *rp, *target;
allow kernel to tell VM extra physical addresses it wants mapped in. used in the future for mapping in local APIC memory.
2009-11-11 13:07:06 +01:00
int err;
Basic VM and other minor improvements. Not complete, probably not fully debugged or optimized.
2008-11-19 13:26:10 +01:00
if(ep == SELF) { ep = m_ptr->m_source; }
if(!isokendpt(ep, &proc_nr)) {
no more kprintf - kernel uses libsys printf now, only kputc is special to the kernel.
2010-03-03 16:45:01 +01:00
printf("do_vmctl: unexpected endpoint %d from VM\n", ep);
Basic VM and other minor improvements. Not complete, probably not fully debugged or optimized.
2008-11-19 13:26:10 +01:00
return EINVAL;
}
p = proc_addr(proc_nr);
switch(m_ptr->SVMCTL_PARAM) {
case VMCTL_CLEAR_PAGEFAULT:
re-establish kernel assert()s. use the regular <assert.h> assert() instead of vmassert() in kernel. throw out some #if 0 code. fix a few assert() conditions. enable by default.
2010-03-10 14:00:05 +01:00
assert(RTS_ISSET(p,RTS_PAGEFAULT));
No locking in kernel code - No locking in RTS_(UN)SET macros - No lock_notify() - Removed unused lock_send() - No lock/unlock macros anymore
2010-02-09 16:26:58 +01:00
RTS_UNSET(p, RTS_PAGEFAULT);
Basic VM and other minor improvements. Not complete, probably not fully debugged or optimized.
2008-11-19 13:26:10 +01:00
return OK;
case VMCTL_MEMREQ_GET:
/* Send VM the information about the memory request. */
if(!(rp = vmrequest))
return ESRCH;
re-establish kernel assert()s. use the regular <assert.h> assert() instead of vmassert() in kernel. throw out some #if 0 code. fix a few assert() conditions. enable by default.
2010-03-10 14:00:05 +01:00
assert(RTS_ISSET(rp, RTS_VMREQUEST));
Primary goal for these changes is: - no longer have kernel have its own page table that is loaded on every kernel entry (trap, interrupt, exception). the primary purpose is to reduce the number of required reloads. Result: - kernel can only access memory of process that was running when kernel was entered - kernel must be mapped into every process page table, so traps to kernel keep working Problem: - kernel must often access memory of arbitrary processes (e.g. send arbitrary processes messages); this can't happen directly any more; usually because that process' page table isn't loaded at all, sometimes because that memory isn't mapped in at all, sometimes because it isn't mapped in read-write. So: - kernel must be able to map in memory of any process, in its own address space. Implementation: - VM and kernel share a range of memory in which addresses of all page tables of all processes are available. This has two purposes: . Kernel has to know what data to copy in order to map in a range . Kernel has to know where to write the data in order to map it in That last point is because kernel has to write in the currently loaded page table. - Processes and kernel are separated through segments; kernel segments haven't changed. - The kernel keeps the process whose page table is currently loaded in 'ptproc.' - If it wants to map in a range of memory, it writes the value of the page directory entry for that range into the page directory entry in the currently loaded map. There is a slot reserved for such purposes. The kernel can then access this memory directly. - In order to do this, its segment has been increased (and the segments of processes start where it ends). - In the pagefault handler, detect if the kernel is doing 'trappable' memory access (i.e. a pagefault isn't a fatal error) and if so, - set the saved instruction pointer to phys_copy_fault, breaking out of phys_copy - set the saved eax register to the address of the page fault, both for sanity checking and for checking in which of the two ranges that phys_copy was called with the fault occured - Some boot-time processes do not have their own page table, and are mapped in with the kernel, and separated with segments. The kernel detects this using HASPT. If such a process has to be scheduled, any page table will work and no page table switch is done. Major changes in kernel are - When accessing user processes memory, kernel no longer explicitly checks before it does so if that memory is OK. It simply makes the mapping (if necessary), tries to do the operation, and traps the pagefault if that memory isn't present; if that happens, the copy function returns EFAULT. So all of the CHECKRANGE_OR_SUSPEND macros are gone. - Kernel no longer has to copy/read and parse page tables. - A message copying optimisation: when messages are copied, and the recipient isn't mapped in, they are copied into a buffer in the kernel. This is done in QueueMess. The next time the recipient is scheduled, this message is copied into its memory. This happens in schedcheck(). This eliminates the mapping/copying step for messages, and makes it easier to deliver messages. This eliminates soft_notify. - Kernel no longer creates a page table at all, so the vm_setbuf and pagetable writing in memory.c is gone. Minor changes in kernel are - ipc_stats thrown out, wasn't used - misc flags all renamed to MF_* - NOREC_* macros to enter and leave functions that should not be called recursively; just sanity checks really - code to fully decode segment selectors and descriptors to print on exceptions - lots of vmassert()s added, only executed if DEBUG_VMASSERT is 1
2009-09-21 16:31:52 +02:00
re-establish kernel assert()s. use the regular <assert.h> assert() instead of vmassert() in kernel. throw out some #if 0 code. fix a few assert() conditions. enable by default.
2010-03-10 14:00:05 +01:00
okendpt(rp->p_vmrequest.target, &proc_nr);
Primary goal for these changes is: - no longer have kernel have its own page table that is loaded on every kernel entry (trap, interrupt, exception). the primary purpose is to reduce the number of required reloads. Result: - kernel can only access memory of process that was running when kernel was entered - kernel must be mapped into every process page table, so traps to kernel keep working Problem: - kernel must often access memory of arbitrary processes (e.g. send arbitrary processes messages); this can't happen directly any more; usually because that process' page table isn't loaded at all, sometimes because that memory isn't mapped in at all, sometimes because it isn't mapped in read-write. So: - kernel must be able to map in memory of any process, in its own address space. Implementation: - VM and kernel share a range of memory in which addresses of all page tables of all processes are available. This has two purposes: . Kernel has to know what data to copy in order to map in a range . Kernel has to know where to write the data in order to map it in That last point is because kernel has to write in the currently loaded page table. - Processes and kernel are separated through segments; kernel segments haven't changed. - The kernel keeps the process whose page table is currently loaded in 'ptproc.' - If it wants to map in a range of memory, it writes the value of the page directory entry for that range into the page directory entry in the currently loaded map. There is a slot reserved for such purposes. The kernel can then access this memory directly. - In order to do this, its segment has been increased (and the segments of processes start where it ends). - In the pagefault handler, detect if the kernel is doing 'trappable' memory access (i.e. a pagefault isn't a fatal error) and if so, - set the saved instruction pointer to phys_copy_fault, breaking out of phys_copy - set the saved eax register to the address of the page fault, both for sanity checking and for checking in which of the two ranges that phys_copy was called with the fault occured - Some boot-time processes do not have their own page table, and are mapped in with the kernel, and separated with segments. The kernel detects this using HASPT. If such a process has to be scheduled, any page table will work and no page table switch is done. Major changes in kernel are - When accessing user processes memory, kernel no longer explicitly checks before it does so if that memory is OK. It simply makes the mapping (if necessary), tries to do the operation, and traps the pagefault if that memory isn't present; if that happens, the copy function returns EFAULT. So all of the CHECKRANGE_OR_SUSPEND macros are gone. - Kernel no longer has to copy/read and parse page tables. - A message copying optimisation: when messages are copied, and the recipient isn't mapped in, they are copied into a buffer in the kernel. This is done in QueueMess. The next time the recipient is scheduled, this message is copied into its memory. This happens in schedcheck(). This eliminates the mapping/copying step for messages, and makes it easier to deliver messages. This eliminates soft_notify. - Kernel no longer creates a page table at all, so the vm_setbuf and pagetable writing in memory.c is gone. Minor changes in kernel are - ipc_stats thrown out, wasn't used - misc flags all renamed to MF_* - NOREC_* macros to enter and leave functions that should not be called recursively; just sanity checks really - code to fully decode segment selectors and descriptors to print on exceptions - lots of vmassert()s added, only executed if DEBUG_VMASSERT is 1
2009-09-21 16:31:52 +02:00
target = proc_addr(proc_nr);
Basic VM and other minor improvements. Not complete, probably not fully debugged or optimized.
2008-11-19 13:26:10 +01:00
/* Reply with request fields. */
Merge of Wu's GSOC 09 branch (src.20090525.r4372.wu) Main changes: - COW optimization for safecopy. - safemap, a grant-based interface for sharing memory regions between processes. - Integration with safemap and complete rework of DS, supporting new data types natively (labels, memory ranges, memory mapped ranges). - For further information: http://wiki.minix3.org/en/SummerOfCode2009/MemoryGrants Additional changes not included in the original Wu's branch: - Fixed unhandled case in VM when using COW optimization for safecopy in case of a block that has already been shared as SMAP. - Better interface and naming scheme for sys_saferevmap and ds_retrieve_map calls. - Better input checking in syslib: check for page alignment when creating memory mapping grants. - DS notifies subscribers when an entry is deleted. - Documented the behavior of indirect grants in case of memory mapping. - Test suite in /usr/src/test/safeperf|safecopy|safemap|ds/* reworked and extended. - Minor fixes and general cleanup. - TO-DO: Grant ids should be generated and managed the way endpoints are to make sure grant slots are never misreused.
2010-01-14 16:24:16 +01:00
switch(rp->p_vmrequest.req_type) {
case VMPTYPE_CHECK:
m_ptr->SVMCTL_MRG_TARGET =
rp->p_vmrequest.target;
m_ptr->SVMCTL_MRG_ADDR =
rp->p_vmrequest.params.check.start;
m_ptr->SVMCTL_MRG_LENGTH =
rp->p_vmrequest.params.check.length;
m_ptr->SVMCTL_MRG_FLAG =
rp->p_vmrequest.params.check.writeflag;
m_ptr->SVMCTL_MRG_REQUESTOR =
(void *) rp->p_endpoint;
break;
case VMPTYPE_SMAP:
case VMPTYPE_SUNMAP:
re-establish kernel assert()s. use the regular <assert.h> assert() instead of vmassert() in kernel. throw out some #if 0 code. fix a few assert() conditions. enable by default.
2010-03-10 14:00:05 +01:00
case VMPTYPE_COWMAP:
assert(RTS_ISSET(target,RTS_VMREQTARGET));
RTS_UNSET(target, RTS_VMREQTARGET);
Merge of Wu's GSOC 09 branch (src.20090525.r4372.wu) Main changes: - COW optimization for safecopy. - safemap, a grant-based interface for sharing memory regions between processes. - Integration with safemap and complete rework of DS, supporting new data types natively (labels, memory ranges, memory mapped ranges). - For further information: http://wiki.minix3.org/en/SummerOfCode2009/MemoryGrants Additional changes not included in the original Wu's branch: - Fixed unhandled case in VM when using COW optimization for safecopy in case of a block that has already been shared as SMAP. - Better interface and naming scheme for sys_saferevmap and ds_retrieve_map calls. - Better input checking in syslib: check for page alignment when creating memory mapping grants. - DS notifies subscribers when an entry is deleted. - Documented the behavior of indirect grants in case of memory mapping. - Test suite in /usr/src/test/safeperf|safecopy|safemap|ds/* reworked and extended. - Minor fixes and general cleanup. - TO-DO: Grant ids should be generated and managed the way endpoints are to make sure grant slots are never misreused.
2010-01-14 16:24:16 +01:00
m_ptr->SVMCTL_MRG_TARGET =
rp->p_vmrequest.target;
m_ptr->SVMCTL_MRG_ADDR =
rp->p_vmrequest.params.map.vir_d;
m_ptr->SVMCTL_MRG_EP2 =
rp->p_vmrequest.params.map.ep_s;
m_ptr->SVMCTL_MRG_ADDR2 =
rp->p_vmrequest.params.map.vir_s;
m_ptr->SVMCTL_MRG_LENGTH =
rp->p_vmrequest.params.map.length;
m_ptr->SVMCTL_MRG_FLAG =
rp->p_vmrequest.params.map.writeflag;
m_ptr->SVMCTL_MRG_REQUESTOR =
(void *) rp->p_endpoint;
break;
default:
panic() cleanup. this change - makes panic() variadic, doing full printf() formatting - no more NO_NUM, and no more separate printf() statements needed to print extra info (or something in hex) before panicing - unifies panic() - same panic() name and usage for everyone - vm, kernel and rest have different names/syntax currently in order to implement their own luxuries, but no longer - throws out the 1st argument, to make source less noisy. the panic() in syslib retrieves the server name from the kernel so it should be clear enough who is panicing; e.g. panic("sigaction failed: %d", errno); looks like: at_wini(73130): panic: sigaction failed: 0 syslib:panic.c: stacktrace: 0x74dc 0x2025 0x100a - throws out report() - printf() is more convenient and powerful - harmonizes/fixes the use of panic() - there were a few places that used printf-style formatting (didn't work) and newlines (messes up the formatting) in panic() - throws out a few per-server panic() functions - cleans up a tie-in of tty with panic() merging printf() and panic() statements to be done incrementally.
2010-03-05 16:05:11 +01:00
panic("VMREQUEST wrong type");
Merge of Wu's GSOC 09 branch (src.20090525.r4372.wu) Main changes: - COW optimization for safecopy. - safemap, a grant-based interface for sharing memory regions between processes. - Integration with safemap and complete rework of DS, supporting new data types natively (labels, memory ranges, memory mapped ranges). - For further information: http://wiki.minix3.org/en/SummerOfCode2009/MemoryGrants Additional changes not included in the original Wu's branch: - Fixed unhandled case in VM when using COW optimization for safecopy in case of a block that has already been shared as SMAP. - Better interface and naming scheme for sys_saferevmap and ds_retrieve_map calls. - Better input checking in syslib: check for page alignment when creating memory mapping grants. - DS notifies subscribers when an entry is deleted. - Documented the behavior of indirect grants in case of memory mapping. - Test suite in /usr/src/test/safeperf|safecopy|safemap|ds/* reworked and extended. - Minor fixes and general cleanup. - TO-DO: Grant ids should be generated and managed the way endpoints are to make sure grant slots are never misreused.
2010-01-14 16:24:16 +01:00
}
Basic VM and other minor improvements. Not complete, probably not fully debugged or optimized.
2008-11-19 13:26:10 +01:00
rp->p_vmrequest.vmresult = VMSUSPEND;
/* Remove from request chain. */
vmrequest = vmrequest->p_vmrequest.nextrequestor;
Merge of Wu's GSOC 09 branch (src.20090525.r4372.wu) Main changes: - COW optimization for safecopy. - safemap, a grant-based interface for sharing memory regions between processes. - Integration with safemap and complete rework of DS, supporting new data types natively (labels, memory ranges, memory mapped ranges). - For further information: http://wiki.minix3.org/en/SummerOfCode2009/MemoryGrants Additional changes not included in the original Wu's branch: - Fixed unhandled case in VM when using COW optimization for safecopy in case of a block that has already been shared as SMAP. - Better interface and naming scheme for sys_saferevmap and ds_retrieve_map calls. - Better input checking in syslib: check for page alignment when creating memory mapping grants. - DS notifies subscribers when an entry is deleted. - Documented the behavior of indirect grants in case of memory mapping. - Test suite in /usr/src/test/safeperf|safecopy|safemap|ds/* reworked and extended. - Minor fixes and general cleanup. - TO-DO: Grant ids should be generated and managed the way endpoints are to make sure grant slots are never misreused.
2010-01-14 16:24:16 +01:00
return rp->p_vmrequest.req_type;
Basic VM and other minor improvements. Not complete, probably not fully debugged or optimized.
2008-11-19 13:26:10 +01:00
case VMCTL_MEMREQ_REPLY:
re-establish kernel assert()s. use the regular <assert.h> assert() instead of vmassert() in kernel. throw out some #if 0 code. fix a few assert() conditions. enable by default.
2010-03-10 14:00:05 +01:00
assert(RTS_ISSET(p, RTS_VMREQUEST));
assert(p->p_vmrequest.vmresult == VMSUSPEND);
Merge of Wu's GSOC 09 branch (src.20090525.r4372.wu) Main changes: - COW optimization for safecopy. - safemap, a grant-based interface for sharing memory regions between processes. - Integration with safemap and complete rework of DS, supporting new data types natively (labels, memory ranges, memory mapped ranges). - For further information: http://wiki.minix3.org/en/SummerOfCode2009/MemoryGrants Additional changes not included in the original Wu's branch: - Fixed unhandled case in VM when using COW optimization for safecopy in case of a block that has already been shared as SMAP. - Better interface and naming scheme for sys_saferevmap and ds_retrieve_map calls. - Better input checking in syslib: check for page alignment when creating memory mapping grants. - DS notifies subscribers when an entry is deleted. - Documented the behavior of indirect grants in case of memory mapping. - Test suite in /usr/src/test/safeperf|safecopy|safemap|ds/* reworked and extended. - Minor fixes and general cleanup. - TO-DO: Grant ids should be generated and managed the way endpoints are to make sure grant slots are never misreused.
2010-01-14 16:24:16 +01:00
okendpt(p->p_vmrequest.target, &proc_nr);
Primary goal for these changes is: - no longer have kernel have its own page table that is loaded on every kernel entry (trap, interrupt, exception). the primary purpose is to reduce the number of required reloads. Result: - kernel can only access memory of process that was running when kernel was entered - kernel must be mapped into every process page table, so traps to kernel keep working Problem: - kernel must often access memory of arbitrary processes (e.g. send arbitrary processes messages); this can't happen directly any more; usually because that process' page table isn't loaded at all, sometimes because that memory isn't mapped in at all, sometimes because it isn't mapped in read-write. So: - kernel must be able to map in memory of any process, in its own address space. Implementation: - VM and kernel share a range of memory in which addresses of all page tables of all processes are available. This has two purposes: . Kernel has to know what data to copy in order to map in a range . Kernel has to know where to write the data in order to map it in That last point is because kernel has to write in the currently loaded page table. - Processes and kernel are separated through segments; kernel segments haven't changed. - The kernel keeps the process whose page table is currently loaded in 'ptproc.' - If it wants to map in a range of memory, it writes the value of the page directory entry for that range into the page directory entry in the currently loaded map. There is a slot reserved for such purposes. The kernel can then access this memory directly. - In order to do this, its segment has been increased (and the segments of processes start where it ends). - In the pagefault handler, detect if the kernel is doing 'trappable' memory access (i.e. a pagefault isn't a fatal error) and if so, - set the saved instruction pointer to phys_copy_fault, breaking out of phys_copy - set the saved eax register to the address of the page fault, both for sanity checking and for checking in which of the two ranges that phys_copy was called with the fault occured - Some boot-time processes do not have their own page table, and are mapped in with the kernel, and separated with segments. The kernel detects this using HASPT. If such a process has to be scheduled, any page table will work and no page table switch is done. Major changes in kernel are - When accessing user processes memory, kernel no longer explicitly checks before it does so if that memory is OK. It simply makes the mapping (if necessary), tries to do the operation, and traps the pagefault if that memory isn't present; if that happens, the copy function returns EFAULT. So all of the CHECKRANGE_OR_SUSPEND macros are gone. - Kernel no longer has to copy/read and parse page tables. - A message copying optimisation: when messages are copied, and the recipient isn't mapped in, they are copied into a buffer in the kernel. This is done in QueueMess. The next time the recipient is scheduled, this message is copied into its memory. This happens in schedcheck(). This eliminates the mapping/copying step for messages, and makes it easier to deliver messages. This eliminates soft_notify. - Kernel no longer creates a page table at all, so the vm_setbuf and pagetable writing in memory.c is gone. Minor changes in kernel are - ipc_stats thrown out, wasn't used - misc flags all renamed to MF_* - NOREC_* macros to enter and leave functions that should not be called recursively; just sanity checks really - code to fully decode segment selectors and descriptors to print on exceptions - lots of vmassert()s added, only executed if DEBUG_VMASSERT is 1
2009-09-21 16:31:52 +02:00
target = proc_addr(proc_nr);
p->p_vmrequest.vmresult = m_ptr->SVMCTL_VALUE;
re-establish kernel assert()s. use the regular <assert.h> assert() instead of vmassert() in kernel. throw out some #if 0 code. fix a few assert() conditions. enable by default.
2010-03-10 14:00:05 +01:00
assert(p->p_vmrequest.vmresult != VMSUSPEND);
Primary goal for these changes is: - no longer have kernel have its own page table that is loaded on every kernel entry (trap, interrupt, exception). the primary purpose is to reduce the number of required reloads. Result: - kernel can only access memory of process that was running when kernel was entered - kernel must be mapped into every process page table, so traps to kernel keep working Problem: - kernel must often access memory of arbitrary processes (e.g. send arbitrary processes messages); this can't happen directly any more; usually because that process' page table isn't loaded at all, sometimes because that memory isn't mapped in at all, sometimes because it isn't mapped in read-write. So: - kernel must be able to map in memory of any process, in its own address space. Implementation: - VM and kernel share a range of memory in which addresses of all page tables of all processes are available. This has two purposes: . Kernel has to know what data to copy in order to map in a range . Kernel has to know where to write the data in order to map it in That last point is because kernel has to write in the currently loaded page table. - Processes and kernel are separated through segments; kernel segments haven't changed. - The kernel keeps the process whose page table is currently loaded in 'ptproc.' - If it wants to map in a range of memory, it writes the value of the page directory entry for that range into the page directory entry in the currently loaded map. There is a slot reserved for such purposes. The kernel can then access this memory directly. - In order to do this, its segment has been increased (and the segments of processes start where it ends). - In the pagefault handler, detect if the kernel is doing 'trappable' memory access (i.e. a pagefault isn't a fatal error) and if so, - set the saved instruction pointer to phys_copy_fault, breaking out of phys_copy - set the saved eax register to the address of the page fault, both for sanity checking and for checking in which of the two ranges that phys_copy was called with the fault occured - Some boot-time processes do not have their own page table, and are mapped in with the kernel, and separated with segments. The kernel detects this using HASPT. If such a process has to be scheduled, any page table will work and no page table switch is done. Major changes in kernel are - When accessing user processes memory, kernel no longer explicitly checks before it does so if that memory is OK. It simply makes the mapping (if necessary), tries to do the operation, and traps the pagefault if that memory isn't present; if that happens, the copy function returns EFAULT. So all of the CHECKRANGE_OR_SUSPEND macros are gone. - Kernel no longer has to copy/read and parse page tables. - A message copying optimisation: when messages are copied, and the recipient isn't mapped in, they are copied into a buffer in the kernel. This is done in QueueMess. The next time the recipient is scheduled, this message is copied into its memory. This happens in schedcheck(). This eliminates the mapping/copying step for messages, and makes it easier to deliver messages. This eliminates soft_notify. - Kernel no longer creates a page table at all, so the vm_setbuf and pagetable writing in memory.c is gone. Minor changes in kernel are - ipc_stats thrown out, wasn't used - misc flags all renamed to MF_* - NOREC_* macros to enter and leave functions that should not be called recursively; just sanity checks really - code to fully decode segment selectors and descriptors to print on exceptions - lots of vmassert()s added, only executed if DEBUG_VMASSERT is 1
2009-09-21 16:31:52 +02:00
Merge of Wu's GSOC 09 branch (src.20090525.r4372.wu) Main changes: - COW optimization for safecopy. - safemap, a grant-based interface for sharing memory regions between processes. - Integration with safemap and complete rework of DS, supporting new data types natively (labels, memory ranges, memory mapped ranges). - For further information: http://wiki.minix3.org/en/SummerOfCode2009/MemoryGrants Additional changes not included in the original Wu's branch: - Fixed unhandled case in VM when using COW optimization for safecopy in case of a block that has already been shared as SMAP. - Better interface and naming scheme for sys_saferevmap and ds_retrieve_map calls. - Better input checking in syslib: check for page alignment when creating memory mapping grants. - DS notifies subscribers when an entry is deleted. - Documented the behavior of indirect grants in case of memory mapping. - Test suite in /usr/src/test/safeperf|safecopy|safemap|ds/* reworked and extended. - Minor fixes and general cleanup. - TO-DO: Grant ids should be generated and managed the way endpoints are to make sure grant slots are never misreused.
2010-01-14 16:24:16 +01:00
switch(p->p_vmrequest.type) {
case VMSTYPE_KERNELCALL:
Removal of the system task * Userspace change to use the new kernel calls - _taskcall(SYSTASK...) changed to _kernel_call(...) - int 32 reused for the kernel calls - _do_kernel_call() to make the trap to kernel - kernel_call() to make the actuall kernel call from C using _do_kernel_call() - unlike ipc call the kernel call always succeeds as kernel is always available, however, kernel may return an error * Kernel side implementation of kernel calls - the SYSTEm task does not run, only the proc table entry is preserved - every data_copy(SYSTEM is no data_copy(KERNEL - "locking" is an empty operation now as everything runs in kernel - sys_task() is replaced by kernel_call() which copies the message into kernel, dispatches the call to its handler and finishes by either copying the results back to userspace (if need be) or by suspending the process because of VM - suspended processes are later made runnable once the memory issue is resolved, picked up by the scheduler and only at this time the call is resumed (in fact restarted) which does not need to copy the message from userspace as the message is already saved in the process structure. - no ned for the vmrestart queue, the scheduler will restart the system calls - no special case in do_vmctl(), all requests remove the RTS_VMREQUEST flag
2010-02-09 16:20:09 +01:00
/*
* we will have to resume execution of the kernel call
* as soon the scheduler picks up this process again
*/
p->p_misc_flags |= MF_KCALL_RESUME;
Merge of Wu's GSOC 09 branch (src.20090525.r4372.wu) Main changes: - COW optimization for safecopy. - safemap, a grant-based interface for sharing memory regions between processes. - Integration with safemap and complete rework of DS, supporting new data types natively (labels, memory ranges, memory mapped ranges). - For further information: http://wiki.minix3.org/en/SummerOfCode2009/MemoryGrants Additional changes not included in the original Wu's branch: - Fixed unhandled case in VM when using COW optimization for safecopy in case of a block that has already been shared as SMAP. - Better interface and naming scheme for sys_saferevmap and ds_retrieve_map calls. - Better input checking in syslib: check for page alignment when creating memory mapping grants. - DS notifies subscribers when an entry is deleted. - Documented the behavior of indirect grants in case of memory mapping. - Test suite in /usr/src/test/safeperf|safecopy|safemap|ds/* reworked and extended. - Minor fixes and general cleanup. - TO-DO: Grant ids should be generated and managed the way endpoints are to make sure grant slots are never misreused.
2010-01-14 16:24:16 +01:00
break;
case VMSTYPE_DELIVERMSG:
re-establish kernel assert()s. use the regular <assert.h> assert() instead of vmassert() in kernel. throw out some #if 0 code. fix a few assert() conditions. enable by default.
2010-03-10 14:00:05 +01:00
assert(p->p_misc_flags & MF_DELIVERMSG);
assert(p == target);
assert(RTS_ISSET(p, RTS_VMREQUEST));
Merge of Wu's GSOC 09 branch (src.20090525.r4372.wu) Main changes: - COW optimization for safecopy. - safemap, a grant-based interface for sharing memory regions between processes. - Integration with safemap and complete rework of DS, supporting new data types natively (labels, memory ranges, memory mapped ranges). - For further information: http://wiki.minix3.org/en/SummerOfCode2009/MemoryGrants Additional changes not included in the original Wu's branch: - Fixed unhandled case in VM when using COW optimization for safecopy in case of a block that has already been shared as SMAP. - Better interface and naming scheme for sys_saferevmap and ds_retrieve_map calls. - Better input checking in syslib: check for page alignment when creating memory mapping grants. - DS notifies subscribers when an entry is deleted. - Documented the behavior of indirect grants in case of memory mapping. - Test suite in /usr/src/test/safeperf|safecopy|safemap|ds/* reworked and extended. - Minor fixes and general cleanup. - TO-DO: Grant ids should be generated and managed the way endpoints are to make sure grant slots are never misreused.
2010-01-14 16:24:16 +01:00
break;
case VMSTYPE_MAP:
re-establish kernel assert()s. use the regular <assert.h> assert() instead of vmassert() in kernel. throw out some #if 0 code. fix a few assert() conditions. enable by default.
2010-03-10 14:00:05 +01:00
assert(RTS_ISSET(p, RTS_VMREQUEST));
Merge of Wu's GSOC 09 branch (src.20090525.r4372.wu) Main changes: - COW optimization for safecopy. - safemap, a grant-based interface for sharing memory regions between processes. - Integration with safemap and complete rework of DS, supporting new data types natively (labels, memory ranges, memory mapped ranges). - For further information: http://wiki.minix3.org/en/SummerOfCode2009/MemoryGrants Additional changes not included in the original Wu's branch: - Fixed unhandled case in VM when using COW optimization for safecopy in case of a block that has already been shared as SMAP. - Better interface and naming scheme for sys_saferevmap and ds_retrieve_map calls. - Better input checking in syslib: check for page alignment when creating memory mapping grants. - DS notifies subscribers when an entry is deleted. - Documented the behavior of indirect grants in case of memory mapping. - Test suite in /usr/src/test/safeperf|safecopy|safemap|ds/* reworked and extended. - Minor fixes and general cleanup. - TO-DO: Grant ids should be generated and managed the way endpoints are to make sure grant slots are never misreused.
2010-01-14 16:24:16 +01:00
break;
default:
re-establish kernel assert()s. use the regular <assert.h> assert() instead of vmassert() in kernel. throw out some #if 0 code. fix a few assert() conditions. enable by default.
2010-03-10 14:00:05 +01:00
panic("strange request type: %d",p->p_vmrequest.type);
Primary goal for these changes is: - no longer have kernel have its own page table that is loaded on every kernel entry (trap, interrupt, exception). the primary purpose is to reduce the number of required reloads. Result: - kernel can only access memory of process that was running when kernel was entered - kernel must be mapped into every process page table, so traps to kernel keep working Problem: - kernel must often access memory of arbitrary processes (e.g. send arbitrary processes messages); this can't happen directly any more; usually because that process' page table isn't loaded at all, sometimes because that memory isn't mapped in at all, sometimes because it isn't mapped in read-write. So: - kernel must be able to map in memory of any process, in its own address space. Implementation: - VM and kernel share a range of memory in which addresses of all page tables of all processes are available. This has two purposes: . Kernel has to know what data to copy in order to map in a range . Kernel has to know where to write the data in order to map it in That last point is because kernel has to write in the currently loaded page table. - Processes and kernel are separated through segments; kernel segments haven't changed. - The kernel keeps the process whose page table is currently loaded in 'ptproc.' - If it wants to map in a range of memory, it writes the value of the page directory entry for that range into the page directory entry in the currently loaded map. There is a slot reserved for such purposes. The kernel can then access this memory directly. - In order to do this, its segment has been increased (and the segments of processes start where it ends). - In the pagefault handler, detect if the kernel is doing 'trappable' memory access (i.e. a pagefault isn't a fatal error) and if so, - set the saved instruction pointer to phys_copy_fault, breaking out of phys_copy - set the saved eax register to the address of the page fault, both for sanity checking and for checking in which of the two ranges that phys_copy was called with the fault occured - Some boot-time processes do not have their own page table, and are mapped in with the kernel, and separated with segments. The kernel detects this using HASPT. If such a process has to be scheduled, any page table will work and no page table switch is done. Major changes in kernel are - When accessing user processes memory, kernel no longer explicitly checks before it does so if that memory is OK. It simply makes the mapping (if necessary), tries to do the operation, and traps the pagefault if that memory isn't present; if that happens, the copy function returns EFAULT. So all of the CHECKRANGE_OR_SUSPEND macros are gone. - Kernel no longer has to copy/read and parse page tables. - A message copying optimisation: when messages are copied, and the recipient isn't mapped in, they are copied into a buffer in the kernel. This is done in QueueMess. The next time the recipient is scheduled, this message is copied into its memory. This happens in schedcheck(). This eliminates the mapping/copying step for messages, and makes it easier to deliver messages. This eliminates soft_notify. - Kernel no longer creates a page table at all, so the vm_setbuf and pagetable writing in memory.c is gone. Minor changes in kernel are - ipc_stats thrown out, wasn't used - misc flags all renamed to MF_* - NOREC_* macros to enter and leave functions that should not be called recursively; just sanity checks really - code to fully decode segment selectors and descriptors to print on exceptions - lots of vmassert()s added, only executed if DEBUG_VMASSERT is 1
2009-09-21 16:31:52 +02:00
}
No locking in kernel code - No locking in RTS_(UN)SET macros - No lock_notify() - Removed unused lock_send() - No lock/unlock macros anymore
2010-02-09 16:26:58 +01:00
RTS_UNSET(p, RTS_VMREQUEST);
Basic VM and other minor improvements. Not complete, probably not fully debugged or optimized.
2008-11-19 13:26:10 +01:00
return OK;
Removal of the system task * Userspace change to use the new kernel calls - _taskcall(SYSTASK...) changed to _kernel_call(...) - int 32 reused for the kernel calls - _do_kernel_call() to make the trap to kernel - kernel_call() to make the actuall kernel call from C using _do_kernel_call() - unlike ipc call the kernel call always succeeds as kernel is always available, however, kernel may return an error * Kernel side implementation of kernel calls - the SYSTEm task does not run, only the proc table entry is preserved - every data_copy(SYSTEM is no data_copy(KERNEL - "locking" is an empty operation now as everything runs in kernel - sys_task() is replaced by kernel_call() which copies the message into kernel, dispatches the call to its handler and finishes by either copying the results back to userspace (if need be) or by suspending the process because of VM - suspended processes are later made runnable once the memory issue is resolved, picked up by the scheduler and only at this time the call is resumed (in fact restarted) which does not need to copy the message from userspace as the message is already saved in the process structure. - no ned for the vmrestart queue, the scheduler will restart the system calls - no special case in do_vmctl(), all requests remove the RTS_VMREQUEST flag
2010-02-09 16:20:09 +01:00
Primary goal for these changes is: - no longer have kernel have its own page table that is loaded on every kernel entry (trap, interrupt, exception). the primary purpose is to reduce the number of required reloads. Result: - kernel can only access memory of process that was running when kernel was entered - kernel must be mapped into every process page table, so traps to kernel keep working Problem: - kernel must often access memory of arbitrary processes (e.g. send arbitrary processes messages); this can't happen directly any more; usually because that process' page table isn't loaded at all, sometimes because that memory isn't mapped in at all, sometimes because it isn't mapped in read-write. So: - kernel must be able to map in memory of any process, in its own address space. Implementation: - VM and kernel share a range of memory in which addresses of all page tables of all processes are available. This has two purposes: . Kernel has to know what data to copy in order to map in a range . Kernel has to know where to write the data in order to map it in That last point is because kernel has to write in the currently loaded page table. - Processes and kernel are separated through segments; kernel segments haven't changed. - The kernel keeps the process whose page table is currently loaded in 'ptproc.' - If it wants to map in a range of memory, it writes the value of the page directory entry for that range into the page directory entry in the currently loaded map. There is a slot reserved for such purposes. The kernel can then access this memory directly. - In order to do this, its segment has been increased (and the segments of processes start where it ends). - In the pagefault handler, detect if the kernel is doing 'trappable' memory access (i.e. a pagefault isn't a fatal error) and if so, - set the saved instruction pointer to phys_copy_fault, breaking out of phys_copy - set the saved eax register to the address of the page fault, both for sanity checking and for checking in which of the two ranges that phys_copy was called with the fault occured - Some boot-time processes do not have their own page table, and are mapped in with the kernel, and separated with segments. The kernel detects this using HASPT. If such a process has to be scheduled, any page table will work and no page table switch is done. Major changes in kernel are - When accessing user processes memory, kernel no longer explicitly checks before it does so if that memory is OK. It simply makes the mapping (if necessary), tries to do the operation, and traps the pagefault if that memory isn't present; if that happens, the copy function returns EFAULT. So all of the CHECKRANGE_OR_SUSPEND macros are gone. - Kernel no longer has to copy/read and parse page tables. - A message copying optimisation: when messages are copied, and the recipient isn't mapped in, they are copied into a buffer in the kernel. This is done in QueueMess. The next time the recipient is scheduled, this message is copied into its memory. This happens in schedcheck(). This eliminates the mapping/copying step for messages, and makes it easier to deliver messages. This eliminates soft_notify. - Kernel no longer creates a page table at all, so the vm_setbuf and pagetable writing in memory.c is gone. Minor changes in kernel are - ipc_stats thrown out, wasn't used - misc flags all renamed to MF_* - NOREC_* macros to enter and leave functions that should not be called recursively; just sanity checks really - code to fully decode segment selectors and descriptors to print on exceptions - lots of vmassert()s added, only executed if DEBUG_VMASSERT is 1
2009-09-21 16:31:52 +02:00
case VMCTL_ENABLE_PAGING:
if(vm_running)
panic() cleanup. this change - makes panic() variadic, doing full printf() formatting - no more NO_NUM, and no more separate printf() statements needed to print extra info (or something in hex) before panicing - unifies panic() - same panic() name and usage for everyone - vm, kernel and rest have different names/syntax currently in order to implement their own luxuries, but no longer - throws out the 1st argument, to make source less noisy. the panic() in syslib retrieves the server name from the kernel so it should be clear enough who is panicing; e.g. panic("sigaction failed: %d", errno); looks like: at_wini(73130): panic: sigaction failed: 0 syslib:panic.c: stacktrace: 0x74dc 0x2025 0x100a - throws out report() - printf() is more convenient and powerful - harmonizes/fixes the use of panic() - there were a few places that used printf-style formatting (didn't work) and newlines (messes up the formatting) in panic() - throws out a few per-server panic() functions - cleans up a tie-in of tty with panic() merging printf() and panic() statements to be done incrementally.
2010-03-05 16:05:11 +01:00
panic("do_vmctl: paging already enabled");
Primary goal for these changes is: - no longer have kernel have its own page table that is loaded on every kernel entry (trap, interrupt, exception). the primary purpose is to reduce the number of required reloads. Result: - kernel can only access memory of process that was running when kernel was entered - kernel must be mapped into every process page table, so traps to kernel keep working Problem: - kernel must often access memory of arbitrary processes (e.g. send arbitrary processes messages); this can't happen directly any more; usually because that process' page table isn't loaded at all, sometimes because that memory isn't mapped in at all, sometimes because it isn't mapped in read-write. So: - kernel must be able to map in memory of any process, in its own address space. Implementation: - VM and kernel share a range of memory in which addresses of all page tables of all processes are available. This has two purposes: . Kernel has to know what data to copy in order to map in a range . Kernel has to know where to write the data in order to map it in That last point is because kernel has to write in the currently loaded page table. - Processes and kernel are separated through segments; kernel segments haven't changed. - The kernel keeps the process whose page table is currently loaded in 'ptproc.' - If it wants to map in a range of memory, it writes the value of the page directory entry for that range into the page directory entry in the currently loaded map. There is a slot reserved for such purposes. The kernel can then access this memory directly. - In order to do this, its segment has been increased (and the segments of processes start where it ends). - In the pagefault handler, detect if the kernel is doing 'trappable' memory access (i.e. a pagefault isn't a fatal error) and if so, - set the saved instruction pointer to phys_copy_fault, breaking out of phys_copy - set the saved eax register to the address of the page fault, both for sanity checking and for checking in which of the two ranges that phys_copy was called with the fault occured - Some boot-time processes do not have their own page table, and are mapped in with the kernel, and separated with segments. The kernel detects this using HASPT. If such a process has to be scheduled, any page table will work and no page table switch is done. Major changes in kernel are - When accessing user processes memory, kernel no longer explicitly checks before it does so if that memory is OK. It simply makes the mapping (if necessary), tries to do the operation, and traps the pagefault if that memory isn't present; if that happens, the copy function returns EFAULT. So all of the CHECKRANGE_OR_SUSPEND macros are gone. - Kernel no longer has to copy/read and parse page tables. - A message copying optimisation: when messages are copied, and the recipient isn't mapped in, they are copied into a buffer in the kernel. This is done in QueueMess. The next time the recipient is scheduled, this message is copied into its memory. This happens in schedcheck(). This eliminates the mapping/copying step for messages, and makes it easier to deliver messages. This eliminates soft_notify. - Kernel no longer creates a page table at all, so the vm_setbuf and pagetable writing in memory.c is gone. Minor changes in kernel are - ipc_stats thrown out, wasn't used - misc flags all renamed to MF_* - NOREC_* macros to enter and leave functions that should not be called recursively; just sanity checks really - code to fully decode segment selectors and descriptors to print on exceptions - lots of vmassert()s added, only executed if DEBUG_VMASSERT is 1
2009-09-21 16:31:52 +02:00
vm_init(p);
if(!vm_running)
panic() cleanup. this change - makes panic() variadic, doing full printf() formatting - no more NO_NUM, and no more separate printf() statements needed to print extra info (or something in hex) before panicing - unifies panic() - same panic() name and usage for everyone - vm, kernel and rest have different names/syntax currently in order to implement their own luxuries, but no longer - throws out the 1st argument, to make source less noisy. the panic() in syslib retrieves the server name from the kernel so it should be clear enough who is panicing; e.g. panic("sigaction failed: %d", errno); looks like: at_wini(73130): panic: sigaction failed: 0 syslib:panic.c: stacktrace: 0x74dc 0x2025 0x100a - throws out report() - printf() is more convenient and powerful - harmonizes/fixes the use of panic() - there were a few places that used printf-style formatting (didn't work) and newlines (messes up the formatting) in panic() - throws out a few per-server panic() functions - cleans up a tie-in of tty with panic() merging printf() and panic() statements to be done incrementally.
2010-03-05 16:05:11 +01:00
panic("do_vmctl: paging enabling failed");
allow kernel to tell VM extra physical addresses it wants mapped in. used in the future for mapping in local APIC memory.
2009-11-11 13:07:06 +01:00
if ((err = arch_enable_paging()) != OK) {
return err;
}
This patch removes the global variables who_p and who_e from the kernel (sys task). The main reason is that these would have to become cpu local variables on SMP. Once the system task is not a task but a genuine part of the kernel there is even less reason to have these extra variables as proc_ptr will already contain all neccessary information. In addition converting who_e to the process pointer and back again all the time will be avoided. Although proc_ptr will contain all important information, accessing it as a cpu local variable will be fairly expensive, hence the value would be assigned to some on stack local variable. Therefore it is better to add the 'caller' argument to the syscall handlers to pass the value on stack anyway. It also clearly denotes on who's behalf is the syscall being executed. This patch also ANSIfies the syscall function headers. Last but not least, it also fixes a potential bug in virtual_copy_f() in case the check is disabled. So far the function in case of a failure could possible reuse an old who_p in case this function had not been called from the system task. virtual_copy_f() takes the caller as a parameter too. In case the checking is disabled, the caller must be NULL and non NULL if it is enabled as we must be able to suspend the caller.
2010-02-03 10:04:48 +01:00
if(newmap(caller, p, (struct mem_map *) m_ptr->SVMCTL_VALUE) != OK)
panic() cleanup. this change - makes panic() variadic, doing full printf() formatting - no more NO_NUM, and no more separate printf() statements needed to print extra info (or something in hex) before panicing - unifies panic() - same panic() name and usage for everyone - vm, kernel and rest have different names/syntax currently in order to implement their own luxuries, but no longer - throws out the 1st argument, to make source less noisy. the panic() in syslib retrieves the server name from the kernel so it should be clear enough who is panicing; e.g. panic("sigaction failed: %d", errno); looks like: at_wini(73130): panic: sigaction failed: 0 syslib:panic.c: stacktrace: 0x74dc 0x2025 0x100a - throws out report() - printf() is more convenient and powerful - harmonizes/fixes the use of panic() - there were a few places that used printf-style formatting (didn't work) and newlines (messes up the formatting) in panic() - throws out a few per-server panic() functions - cleans up a tie-in of tty with panic() merging printf() and panic() statements to be done incrementally.
2010-03-05 16:05:11 +01:00
panic("do_vmctl: newmap failed");
Primary goal for these changes is: - no longer have kernel have its own page table that is loaded on every kernel entry (trap, interrupt, exception). the primary purpose is to reduce the number of required reloads. Result: - kernel can only access memory of process that was running when kernel was entered - kernel must be mapped into every process page table, so traps to kernel keep working Problem: - kernel must often access memory of arbitrary processes (e.g. send arbitrary processes messages); this can't happen directly any more; usually because that process' page table isn't loaded at all, sometimes because that memory isn't mapped in at all, sometimes because it isn't mapped in read-write. So: - kernel must be able to map in memory of any process, in its own address space. Implementation: - VM and kernel share a range of memory in which addresses of all page tables of all processes are available. This has two purposes: . Kernel has to know what data to copy in order to map in a range . Kernel has to know where to write the data in order to map it in That last point is because kernel has to write in the currently loaded page table. - Processes and kernel are separated through segments; kernel segments haven't changed. - The kernel keeps the process whose page table is currently loaded in 'ptproc.' - If it wants to map in a range of memory, it writes the value of the page directory entry for that range into the page directory entry in the currently loaded map. There is a slot reserved for such purposes. The kernel can then access this memory directly. - In order to do this, its segment has been increased (and the segments of processes start where it ends). - In the pagefault handler, detect if the kernel is doing 'trappable' memory access (i.e. a pagefault isn't a fatal error) and if so, - set the saved instruction pointer to phys_copy_fault, breaking out of phys_copy - set the saved eax register to the address of the page fault, both for sanity checking and for checking in which of the two ranges that phys_copy was called with the fault occured - Some boot-time processes do not have their own page table, and are mapped in with the kernel, and separated with segments. The kernel detects this using HASPT. If such a process has to be scheduled, any page table will work and no page table switch is done. Major changes in kernel are - When accessing user processes memory, kernel no longer explicitly checks before it does so if that memory is OK. It simply makes the mapping (if necessary), tries to do the operation, and traps the pagefault if that memory isn't present; if that happens, the copy function returns EFAULT. So all of the CHECKRANGE_OR_SUSPEND macros are gone. - Kernel no longer has to copy/read and parse page tables. - A message copying optimisation: when messages are copied, and the recipient isn't mapped in, they are copied into a buffer in the kernel. This is done in QueueMess. The next time the recipient is scheduled, this message is copied into its memory. This happens in schedcheck(). This eliminates the mapping/copying step for messages, and makes it easier to deliver messages. This eliminates soft_notify. - Kernel no longer creates a page table at all, so the vm_setbuf and pagetable writing in memory.c is gone. Minor changes in kernel are - ipc_stats thrown out, wasn't used - misc flags all renamed to MF_* - NOREC_* macros to enter and leave functions that should not be called recursively; just sanity checks really - code to fully decode segment selectors and descriptors to print on exceptions - lots of vmassert()s added, only executed if DEBUG_VMASSERT is 1
2009-09-21 16:31:52 +02:00
FIXLINMSG(p);
re-establish kernel assert()s. use the regular <assert.h> assert() instead of vmassert() in kernel. throw out some #if 0 code. fix a few assert() conditions. enable by default.
2010-03-10 14:00:05 +01:00
assert(p->p_delivermsg_lin ==
umap_local(p, D, p->p_delivermsg_vir, sizeof(message)));
make kernel leave a page-sized gap in its code and data to not be mapped in if so configured.
2008-12-18 15:30:55 +01:00
return OK;
allow kernel to tell VM extra physical addresses it wants mapped in. used in the future for mapping in local APIC memory.
2009-11-11 13:07:06 +01:00
case VMCTL_KERN_PHYSMAP:
{
int i = m_ptr->SVMCTL_VALUE;
return arch_phys_map(i,
(phys_bytes *) &m_ptr->SVMCTL_MAP_PHYS_ADDR,
(phys_bytes *) &m_ptr->SVMCTL_MAP_PHYS_LEN,
&m_ptr->SVMCTL_MAP_FLAGS);
}
case VMCTL_KERN_MAP_REPLY:
{
return arch_phys_map_reply(m_ptr->SVMCTL_VALUE,
(vir_bytes) m_ptr->SVMCTL_MAP_VIR_ADDR);
}
Basic VM and other minor improvements. Not complete, probably not fully debugged or optimized.
2008-11-19 13:26:10 +01:00
}
/* Try architecture-specific vmctls. */
return arch_do_vmctl(m_ptr, p);
}
Reference in a new issue Copy permalink