KVM: MMU: add SPTE_HOST_WRITEABLE flag to the shadow ptes (1403283a) · Commits · 戴 / test

arch/x86/kvm/mmu.c

+11 −4

Original line number	Diff line number	Diff line
		@@ -156,6 +156,8 @@ module_param(oos_shadow, bool, 0644);
		#define CREATE_TRACE_POINTS
		#include "mmutrace.h"

		#define SPTE_HOST_WRITEABLE (1ULL << PT_FIRST_AVAIL_BITS_SHIFT)

		#define SHADOW_PT_INDEX(addr, level) PT64_INDEX(addr, level)

		struct kvm_rmap_desc {
		@@ -1754,7 +1756,7 @@ static int set_spte(struct kvm_vcpu vcpu, u64 sptep,
		unsigned pte_access, int user_fault,
		int write_fault, int dirty, int level,
		gfn_t gfn, pfn_t pfn, bool speculative,
		bool can_unsync)
		bool can_unsync, bool reset_host_protection)
		{
		u64 spte;
		int ret = 0;
		@@ -1781,6 +1783,9 @@ static int set_spte(struct kvm_vcpu vcpu, u64 sptep,
		spte \|= kvm_x86_ops->get_mt_mask(vcpu, gfn,
		kvm_is_mmio_pfn(pfn));

		if (reset_host_protection)
		spte \|= SPTE_HOST_WRITEABLE;

		spte \|= (u64)pfn << PAGE_SHIFT;

		if ((pte_access & ACC_WRITE_MASK)
		@@ -1826,7 +1831,8 @@ static void mmu_set_spte(struct kvm_vcpu vcpu, u64 sptep,
		unsigned pt_access, unsigned pte_access,
		int user_fault, int write_fault, int dirty,
		int *ptwrite, int level, gfn_t gfn,
		pfn_t pfn, bool speculative)
		pfn_t pfn, bool speculative,
		bool reset_host_protection)
		{
		int was_rmapped = 0;
		int was_writeble = is_writeble_pte(*sptep);
		@@ -1858,7 +1864,8 @@ static void mmu_set_spte(struct kvm_vcpu vcpu, u64 sptep,
		}

		if (set_spte(vcpu, sptep, pte_access, user_fault, write_fault,
		dirty, level, gfn, pfn, speculative, true)) {
		dirty, level, gfn, pfn, speculative, true,
		reset_host_protection)) {
		if (write_fault)
		*ptwrite = 1;
		kvm_x86_ops->tlb_flush(vcpu);
		@@ -1906,7 +1913,7 @@ static int __direct_map(struct kvm_vcpu *vcpu, gpa_t v, int write,
		if (iterator.level == level) {
		mmu_set_spte(vcpu, iterator.sptep, ACC_ALL, ACC_ALL,
		0, write, 1, &pt_write,
		level, gfn, pfn, false);
		level, gfn, pfn, false, true);
		++vcpu->stat.pf_fixed;
		break;
		}

arch/x86/kvm/paging_tmpl.h

+15 −3

Original line number	Diff line number	Diff line
		@@ -273,9 +273,13 @@ static void FNAME(update_pte)(struct kvm_vcpu vcpu, struct kvm_mmu_page page,
		if (mmu_notifier_retry(vcpu, vcpu->arch.update_pte.mmu_seq))
		return;
		kvm_get_pfn(pfn);
		/*
		* we call mmu_set_spte() with reset_host_protection = true beacuse that
		* vcpu->arch.update_pte.pfn was fetched from get_user_pages(write = 1).
		*/
		mmu_set_spte(vcpu, spte, page->role.access, pte_access, 0, 0,
		gpte & PT_DIRTY_MASK, NULL, PT_PAGE_TABLE_LEVEL,
		gpte_to_gfn(gpte), pfn, true);
		gpte_to_gfn(gpte), pfn, true, true);
		}

		/*
		@@ -308,7 +312,7 @@ static u64 FNAME(fetch)(struct kvm_vcpu vcpu, gva_t addr,
		user_fault, write_fault,
		gw->ptes[gw->level-1] & PT_DIRTY_MASK,
		ptwrite, level,
		gw->gfn, pfn, false);
		gw->gfn, pfn, false, true);
		break;
		}

		@@ -558,6 +562,7 @@ static void FNAME(prefetch_page)(struct kvm_vcpu *vcpu,
		static int FNAME(sync_page)(struct kvm_vcpu vcpu, struct kvm_mmu_page sp)
		{
		int i, offset, nr_present;
		bool reset_host_protection;

		offset = nr_present = 0;

		@@ -595,9 +600,16 @@ static int FNAME(sync_page)(struct kvm_vcpu vcpu, struct kvm_mmu_page sp)

		nr_present++;
		pte_access = sp->role.access & FNAME(gpte_access)(vcpu, gpte);
		if (!(sp->spt[i] & SPTE_HOST_WRITEABLE)) {
		pte_access &= ~ACC_WRITE_MASK;
		reset_host_protection = 0;
		} else {
		reset_host_protection = 1;
		}
		set_spte(vcpu, &sp->spt[i], pte_access, 0, 0,
		is_dirty_gpte(gpte), PT_PAGE_TABLE_LEVEL, gfn,
		spte_to_pfn(sp->spt[i]), true, false);
		spte_to_pfn(sp->spt[i]), true, false,
		reset_host_protection);
		}

		return !nr_present;

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