minix3/kernel/system/do_vmctl.c

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2020-02-21 00:59:27 +05:30
/* 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 "kernel/system.h"
#include "kernel/vm.h"
#include "kernel/debug.h"
#include <assert.h>
#include <minix/type.h>
/*===========================================================================*
* do_vmctl *
*===========================================================================*/
int do_vmctl(struct proc * caller, message * m_ptr)
{
int proc_nr;
endpoint_t ep = m_ptr->SVMCTL_WHO;
struct proc *p, *rp, *target;
if(ep == SELF) { ep = caller->p_endpoint; }
if(!isokendpt(ep, &proc_nr)) {
printf("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:
assert(RTS_ISSET(p,RTS_PAGEFAULT));
RTS_UNSET(p, RTS_PAGEFAULT);
return OK;
case VMCTL_MEMREQ_GET:
/* Send VM the information about the memory request. */
if(!(rp = vmrequest))
return ESRCH;
assert(RTS_ISSET(rp, RTS_VMREQUEST));
okendpt(rp->p_vmrequest.target, &proc_nr);
target = proc_addr(proc_nr);
/* 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;
default:
panic("VMREQUEST wrong type");
}
rp->p_vmrequest.vmresult = VMSUSPEND;
/* Remove from request chain. */
vmrequest = vmrequest->p_vmrequest.nextrequestor;
return rp->p_vmrequest.req_type;
case VMCTL_MEMREQ_REPLY:
assert(RTS_ISSET(p, RTS_VMREQUEST));
assert(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;
assert(p->p_vmrequest.vmresult != VMSUSPEND);
switch(p->p_vmrequest.type) {
case VMSTYPE_KERNELCALL:
/*
* 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;
break;
case VMSTYPE_DELIVERMSG:
assert(p->p_misc_flags & MF_DELIVERMSG);
assert(p == target);
assert(RTS_ISSET(p, RTS_VMREQUEST));
break;
case VMSTYPE_MAP:
assert(RTS_ISSET(p, RTS_VMREQUEST));
break;
default:
panic("strange request type: %d",p->p_vmrequest.type);
}
RTS_UNSET(p, RTS_VMREQUEST);
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);
}
case VMCTL_VMINHIBIT_SET:
/* check if we must stop a process on a different CPU */
#if CONFIG_SMP
if (p->p_cpu != cpuid) {
smp_schedule_vminhibit(p);
} else
#endif
RTS_SET(p, RTS_VMINHIBIT);
#if CONFIG_SMP
p->p_misc_flags |= MF_FLUSH_TLB;
#endif
return OK;
case VMCTL_VMINHIBIT_CLEAR:
assert(RTS_ISSET(p, RTS_VMINHIBIT));
/*
* the processes is certainly not runnable, no need to tell its
* cpu
*/
RTS_UNSET(p, RTS_VMINHIBIT);
#ifdef CONFIG_SMP
if (p->p_misc_flags & MF_SENDA_VM_MISS) {
struct priv *privp;
p->p_misc_flags &= ~MF_SENDA_VM_MISS;
privp = priv(p);
try_deliver_senda(p, (asynmsg_t *) privp->s_asyntab,
privp->s_asynsize);
}
/*
* We don't know whether kernel has the changed mapping
* installed to access userspace memory. And if so, on what CPU.
* More over we don't know what mapping has changed and how and
* therefore we must invalidate all mappings we have anywhere.
* Next time we map memory, we map it fresh.
*/
bits_fill(p->p_stale_tlb, CONFIG_MAX_CPUS);
#endif
return OK;
case VMCTL_CLEARMAPCACHE:
/* VM says: forget about old mappings we have cached. */
mem_clear_mapcache();
return OK;
case VMCTL_BOOTINHIBIT_CLEAR:
RTS_UNSET(p, RTS_BOOTINHIBIT);
return OK;
}
/* Try architecture-specific vmctls. */
return arch_do_vmctl(m_ptr, p);
}