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Commit bab4165e authored by Bandan Das's avatar Bandan Das Committed by Paolo Bonzini
Browse files

kvm: x86: Add a hook for arch specific dirty logging emulation 



When KVM updates accessed/dirty bits, this hook can be used
to invoke an arch specific function that implements/emulates
dirty logging such as PML.

Signed-off-by: default avatarBandan Das <bsd@redhat.com>
Signed-off-by: default avatarPaolo Bonzini <pbonzini@redhat.com>
parent c7c2c709

arch/x86/include/asm/kvm_host.h

+2 −0
Original line number Diff line number Diff line
@@ -1020,6 +1020,8 @@ 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);



	/* pmu operations of sub-arch */

	const struct kvm_pmu_ops *pmu_ops;

arch/x86/kvm/mmu.c

+15 −0
Original line number Diff line number Diff line
@@ -1498,6 +1498,21 @@ void kvm_arch_mmu_enable_log_dirty_pt_masked(struct kvm *kvm, 
		kvm_mmu_write_protect_pt_masked(kvm, slot, gfn_offset, mask);

}



/**

 * kvm_arch_write_log_dirty - emulate dirty page logging

 * @vcpu: Guest mode vcpu

 *

 * Emulate arch specific page modification logging for the

 * nested hypervisor

 */

int kvm_arch_write_log_dirty(struct kvm_vcpu *vcpu)

{

	if (kvm_x86_ops->write_log_dirty)

		return kvm_x86_ops->write_log_dirty(vcpu);



	return 0;

}



bool kvm_mmu_slot_gfn_write_protect(struct kvm *kvm,

				    struct kvm_memory_slot *slot, u64 gfn)

{

arch/x86/kvm/mmu.h

+1 −0
Original line number Diff line number Diff line
@@ -202,4 +202,5 @@ 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);

#endif

arch/x86/kvm/paging_tmpl.h

+4 −0
Original line number Diff line number Diff line
@@ -226,6 +226,10 @@ static int FNAME(update_accessed_dirty_bits)(struct kvm_vcpu *vcpu, 
		if (level == walker->level && write_fault &&

				!(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))

				return -EINVAL;

#endif

			pte |= PT_GUEST_DIRTY_MASK;

		}

		if (pte == orig_pte)