Commit 2dbebf7a authored by Sean Christopherson's avatar Sean Christopherson Committed by Paolo Bonzini
Browse files

KVM: nVMX: Plumb L2 GPA through to PML emulation 



Explicitly pass the L2 GPA to kvm_arch_write_log_dirty(), which for all
intents and purposes is vmx_write_pml_buffer(), instead of having the
latter pull the GPA from vmcs.GUEST_PHYSICAL_ADDRESS.  If the dirty bit
update is the result of KVM emulation (rare for L2), then the GPA in the
VMCS may be stale and/or hold a completely unrelated GPA.

Fixes: c5f983f6 ("nVMX: Implement emulated Page Modification Logging")
Cc: stable@vger.kernel.org
Signed-off-by: default avatarSean Christopherson <sean.j.christopherson@intel.com>
Message-Id: <20200622215832.22090-2-sean.j.christopherson@intel.com>
Signed-off-by: default avatarPaolo Bonzini <pbonzini@redhat.com>
parent 312d16c7

arch/x86/include/asm/kvm_host.h

+1 −1
Original line number Diff line number Diff line
@@ -1220,7 +1220,7 @@ struct kvm_x86_ops { 
	void (*enable_log_dirty_pt_masked)(struct kvm *kvm,

					   struct kvm_memory_slot *slot,

					   gfn_t offset, unsigned long mask);

	int (*write_log_dirty)(struct kvm_vcpu *vcpu);

	int (*write_log_dirty)(struct kvm_vcpu *vcpu, gpa_t l2_gpa);



	/* pmu operations of sub-arch */

	const struct kvm_pmu_ops *pmu_ops;

arch/x86/kvm/mmu.h

+1 −1
Original line number Diff line number Diff line
@@ -222,7 +222,7 @@ void kvm_mmu_gfn_disallow_lpage(struct kvm_memory_slot *slot, gfn_t gfn); 
void kvm_mmu_gfn_allow_lpage(struct kvm_memory_slot *slot, gfn_t gfn);

bool kvm_mmu_slot_gfn_write_protect(struct kvm *kvm,

				    struct kvm_memory_slot *slot, u64 gfn);

int kvm_arch_write_log_dirty(struct kvm_vcpu *vcpu);

int kvm_arch_write_log_dirty(struct kvm_vcpu *vcpu, gpa_t l2_gpa);



int kvm_mmu_post_init_vm(struct kvm *kvm);

void kvm_mmu_pre_destroy_vm(struct kvm *kvm);

arch/x86/kvm/mmu/mmu.c

+2 −2
Original line number Diff line number Diff line
@@ -1745,10 +1745,10 @@ void kvm_arch_mmu_enable_log_dirty_pt_masked(struct kvm *kvm, 
 * Emulate arch specific page modification logging for the

 * nested hypervisor

 */

int kvm_arch_write_log_dirty(struct kvm_vcpu *vcpu)

int kvm_arch_write_log_dirty(struct kvm_vcpu *vcpu, gpa_t l2_gpa)

{

	if (kvm_x86_ops.write_log_dirty)

		return kvm_x86_ops.write_log_dirty(vcpu);

		return kvm_x86_ops.write_log_dirty(vcpu, l2_gpa);



	return 0;

}

arch/x86/kvm/mmu/paging_tmpl.h

+4 −3
Original line number Diff line number Diff line
@@ -235,7 +235,7 @@ static inline unsigned FNAME(gpte_access)(u64 gpte) 
static int FNAME(update_accessed_dirty_bits)(struct kvm_vcpu *vcpu,

					     struct kvm_mmu *mmu,

					     struct guest_walker *walker,

					     int write_fault)

					     gpa_t addr, int write_fault)

{

	unsigned level, index;

	pt_element_t pte, orig_pte;
@@ -260,7 +260,7 @@ static int FNAME(update_accessed_dirty_bits)(struct kvm_vcpu *vcpu, 
				!(pte & PT_GUEST_DIRTY_MASK)) {

			trace_kvm_mmu_set_dirty_bit(table_gfn, index, sizeof(pte));

#if PTTYPE == PTTYPE_EPT

			if (kvm_arch_write_log_dirty(vcpu))

			if (kvm_arch_write_log_dirty(vcpu, addr))

				return -EINVAL;

#endif

			pte |= PT_GUEST_DIRTY_MASK;
@@ -454,7 +454,8 @@ retry_walk: 
			(PT_GUEST_DIRTY_SHIFT - PT_GUEST_ACCESSED_SHIFT);



	if (unlikely(!accessed_dirty)) {

		ret = FNAME(update_accessed_dirty_bits)(vcpu, mmu, walker, write_fault);

		ret = FNAME(update_accessed_dirty_bits)(vcpu, mmu, walker,

							addr, write_fault);

		if (unlikely(ret < 0))

			goto error;

		else if (ret)

arch/x86/kvm/vmx/vmx.c

+3 −3
Original line number Diff line number Diff line
@@ -7500,11 +7500,11 @@ static void vmx_flush_log_dirty(struct kvm *kvm) 
	kvm_flush_pml_buffers(kvm);

}



static int vmx_write_pml_buffer(struct kvm_vcpu *vcpu)

static int vmx_write_pml_buffer(struct kvm_vcpu *vcpu, gpa_t gpa)

{

	struct vmcs12 *vmcs12;

	struct vcpu_vmx *vmx = to_vmx(vcpu);

	gpa_t gpa, dst;

	gpa_t dst;



	if (is_guest_mode(vcpu)) {

		WARN_ON_ONCE(vmx->nested.pml_full);
@@ -7523,7 +7523,7 @@ static int vmx_write_pml_buffer(struct kvm_vcpu *vcpu) 
			return 1;

		}



		gpa = vmcs_read64(GUEST_PHYSICAL_ADDRESS) & ~0xFFFull;

		gpa &= ~0xFFFull;

		dst = vmcs12->pml_address + sizeof(u64) * vmcs12->guest_pml_index;



		if (kvm_write_guest_page(vcpu->kvm, gpa_to_gfn(dst), &gpa,

CRA Git | Maintained and supported by SUSTech CRA and CCSE