f51eea4b32
this patch changes the way pagefaults are delivered to VM. It adopts the same model as the out-of-quantum messages sent by kernel to a scheduler. - everytime a userspace pagefault occurs, kernel creates a message which is sent to VM on behalf of the faulting process - the process is blocked on delivery to VM in the standard IPC code instead of waiting in a spacial in-kernel queue (stack) and is not runnable until VM tell kernel that the pagefault is resolved and is free to clear the RTS_PAGEFAULT flag. - VM does not need call kernel and poll the pagefault information which saves many (1/2?) calls and kernel calls that return "no more data" - VM notification by kernel does not need to use signals - each entry in proc table is by 12 bytes smaller (~3k save)
73 lines
1.6 KiB
C
73 lines
1.6 KiB
C
/* The kernel call implemented in this file:
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* m_type: SYS_VMCTL
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*
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* The parameters for this kernel call are:
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* SVMCTL_WHO which process
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* SVMCTL_PARAM set this setting (VMCTL_*)
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* SVMCTL_VALUE to this value
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*/
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#include "kernel/system.h"
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#include <minix/type.h>
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#include "proto.h"
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extern u8_t *vm_pagedirs;
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/*===========================================================================*
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* arch_do_vmctl *
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*===========================================================================*/
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PUBLIC int arch_do_vmctl(m_ptr, p)
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register message *m_ptr; /* pointer to request message */
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struct proc *p;
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{
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switch(m_ptr->SVMCTL_PARAM) {
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case VMCTL_I386_GETCR3:
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/* Get process CR3. */
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m_ptr->SVMCTL_VALUE = p->p_seg.p_cr3;
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return OK;
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case VMCTL_I386_SETCR3:
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/* Set process CR3. */
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if(m_ptr->SVMCTL_VALUE) {
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p->p_seg.p_cr3 = m_ptr->SVMCTL_VALUE;
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p->p_misc_flags |= MF_FULLVM;
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} else {
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p->p_seg.p_cr3 = 0;
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p->p_misc_flags &= ~MF_FULLVM;
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}
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RTS_UNSET(p, RTS_VMINHIBIT);
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return OK;
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case VMCTL_INCSP:
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/* Increase process SP. */
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p->p_reg.sp += m_ptr->SVMCTL_VALUE;
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return OK;
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case VMCTL_I386_KERNELLIMIT:
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{
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int r;
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/* VM wants kernel to increase its segment. */
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r = prot_set_kern_seg_limit(m_ptr->SVMCTL_VALUE);
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return r;
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}
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case VMCTL_I386_PAGEDIRS:
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{
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vm_pagedirs = (u8_t *) m_ptr->SVMCTL_VALUE;
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return OK;
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}
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case VMCTL_I386_FREEPDE:
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{
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i386_freepde(m_ptr->SVMCTL_VALUE);
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return OK;
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}
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case VMCTL_FLUSHTLB:
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{
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reload_cr3();
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return OK;
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}
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}
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printf("arch_do_vmctl: strange param %d\n", m_ptr->SVMCTL_PARAM);
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return EINVAL;
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}
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