minix/kernel/system/do_vmctl.c
Cristiano Giuffrida c5b309ff07 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 15:24:16 +00:00

198 lines
5.5 KiB
C

/* 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"
#include <minix/type.h>
#include <minix/config.h>
/*===========================================================================*
* do_vmctl *
*===========================================================================*/
PUBLIC int do_vmctl(m_ptr)
register message *m_ptr; /* pointer to request message */
{
int proc_nr, i;
endpoint_t ep = m_ptr->SVMCTL_WHO;
struct proc *p, *rp, *target;
int err;
if(ep == SELF) { ep = m_ptr->m_source; }
if(!isokendpt(ep, &proc_nr)) {
kprintf("do_vmctl: unexpected endpoint %d from VM\n", ep);
return EINVAL;
}
p = proc_addr(proc_nr);
switch(m_ptr->SVMCTL_PARAM) {
case VMCTL_CLEAR_PAGEFAULT:
RTS_LOCK_UNSET(p, RTS_PAGEFAULT);
return OK;
case VMCTL_MEMREQ_GET:
/* Send VM the information about the memory request. */
if(!(rp = vmrequest))
return ESRCH;
vmassert(RTS_ISSET(rp, RTS_VMREQUEST));
#if 0
printf("kernel: vm request sent by: %s / %d about %d; 0x%lx-0x%lx, wr %d, stack: %s ",
rp->p_name, rp->p_endpoint, rp->p_vmrequest.who,
rp->p_vmrequest.start,
rp->p_vmrequest.start + rp->p_vmrequest.length,
rp->p_vmrequest.writeflag, rp->p_vmrequest.stacktrace);
printf("type %d\n", rp->p_vmrequest.type);
#endif
#if DEBUG_VMASSERT
okendpt(rp->p_vmrequest.who, &proc_nr);
target = proc_addr(proc_nr);
#if 0
if(!RTS_ISSET(target, RTS_VMREQTARGET)) {
printf("set stack: %s\n", rp->p_vmrequest.stacktrace);
minix_panic("RTS_VMREQTARGET not set for target",
NO_NUM);
}
#endif
#endif
/* Reply with request fields. */
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_COWMAP:
case VMPTYPE_SMAP:
case VMPTYPE_SUNMAP:
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:
minix_panic("VMREQUEST wrong type", NO_NUM);
}
rp->p_vmrequest.vmresult = VMSUSPEND;
/* Remove from request chain. */
vmrequest = vmrequest->p_vmrequest.nextrequestor;
return rp->p_vmrequest.req_type;
case VMCTL_MEMREQ_REPLY:
vmassert(RTS_ISSET(p, RTS_VMREQUEST));
vmassert(p->p_vmrequest.vmresult == VMSUSPEND);
okendpt(p->p_vmrequest.target, &proc_nr);
target = proc_addr(proc_nr);
p->p_vmrequest.vmresult = m_ptr->SVMCTL_VALUE;
vmassert(p->p_vmrequest.vmresult != VMSUSPEND);
#if DEBUG_VMASSERT
if(p->p_vmrequest.vmresult != OK)
kprintf("SYSTEM: VM replied %d to mem request\n",
p->p_vmrequest.vmresult);
printf("memreq reply: vm request sent by: %s / %d about %d; 0x%lx-0x%lx, wr %d, stack: %s ",
p->p_name, p->p_endpoint, p->p_vmrequest.who,
p->p_vmrequest.start,
p->p_vmrequest.start + p->p_vmrequest.length,
p->p_vmrequest.writeflag, p->p_vmrequest.stacktrace);
printf("type %d\n", p->p_vmrequest.type);
#endif
vmassert(RTS_ISSET(target, RTS_VMREQTARGET));
RTS_LOCK_UNSET(target, RTS_VMREQTARGET);
switch(p->p_vmrequest.type) {
case VMSTYPE_KERNELCALL:
/* Put on restart chain. */
p->p_vmrequest.nextrestart = vmrestart;
vmrestart = p;
break;
case VMSTYPE_DELIVERMSG:
vmassert(p->p_misc_flags & MF_DELIVERMSG);
vmassert(p == target);
vmassert(RTS_ISSET(p, RTS_VMREQUEST));
RTS_LOCK_UNSET(p, RTS_VMREQUEST);
break;
case VMSTYPE_MAP:
vmassert(RTS_ISSET(p, RTS_VMREQUEST));
RTS_LOCK_UNSET(p, RTS_VMREQUEST);
break;
default:
#if DEBUG_VMASSERT
printf("suspended with stack: %s\n",
p->p_vmrequest.stacktrace);
#endif
minix_panic("strange request type",
p->p_vmrequest.type);
}
return OK;
case VMCTL_ENABLE_PAGING:
/*
* system task must not get preempted while switching to paging,
* interrupt handling is not safe
*/
lock;
if(vm_running)
minix_panic("do_vmctl: paging already enabled", NO_NUM);
vm_init(p);
if(!vm_running)
minix_panic("do_vmctl: paging enabling failed", NO_NUM);
vmassert(p->p_delivermsg_lin ==
umap_local(p, D, p->p_delivermsg_vir, sizeof(message)));
if ((err = arch_enable_paging()) != OK) {
unlock;
return err;
}
if(newmap(p, (struct mem_map *) m_ptr->SVMCTL_VALUE) != OK)
minix_panic("do_vmctl: newmap failed", NO_NUM);
FIXLINMSG(p);
vmassert(p->p_delivermsg_lin);
unlock;
return OK;
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);
}
}
/* Try architecture-specific vmctls. */
return arch_do_vmctl(m_ptr, p);
}