Commit ee661d8e authored by David Matlack's avatar David Matlack Committed by Sean Christopherson
Browse files

KVM: x86: Replace cpu_dirty_logging_count with nr_memslots_dirty_logging 



Drop cpu_dirty_logging_count in favor of nr_memslots_dirty_logging.
Both fields count the number of memslots that have dirty-logging enabled,
with the only difference being that cpu_dirty_logging_count is only
incremented when using PML. So while nr_memslots_dirty_logging is not a
direct replacement for cpu_dirty_logging_count, it can be combined with
enable_pml to get the same information.

Signed-off-by: default avatarDavid Matlack <dmatlack@google.com>
Link: https://lore.kernel.org/r/20230105214303.2919415-1-dmatlack@google.com


Signed-off-by: default avatarSean Christopherson <seanjc@google.com>
parent 6213b701

arch/x86/include/asm/kvm_host.h

+0 −1
Original line number Diff line number Diff line
@@ -1327,7 +1327,6 @@ struct kvm_arch { 
	u32 bsp_vcpu_id;



	u64 disabled_quirks;

	int cpu_dirty_logging_count;



	enum kvm_irqchip_mode irqchip_mode;

	u8 nr_reserved_ioapic_pins;

arch/x86/kvm/vmx/vmx.c

+6 −3
Original line number Diff line number Diff line
@@ -4606,7 +4606,7 @@ static u32 vmx_secondary_exec_control(struct vcpu_vmx *vmx) 
	 * it needs to be set here when dirty logging is already active, e.g.

	 * if this vCPU was created after dirty logging was enabled.

	 */

	if (!vcpu->kvm->arch.cpu_dirty_logging_count)

	if (!enable_pml || !atomic_read(&vcpu->kvm->nr_memslots_dirty_logging))

		exec_control &= ~SECONDARY_EXEC_ENABLE_PML;



	if (cpu_has_vmx_xsaves()) {
@@ -7988,17 +7988,20 @@ void vmx_update_cpu_dirty_logging(struct kvm_vcpu *vcpu) 
{

	struct vcpu_vmx *vmx = to_vmx(vcpu);



	if (WARN_ON_ONCE(!enable_pml))

		return;



	if (is_guest_mode(vcpu)) {

		vmx->nested.update_vmcs01_cpu_dirty_logging = true;

		return;

	}



	/*

	 * Note, cpu_dirty_logging_count can be changed concurrent with this

	 * Note, nr_memslots_dirty_logging can be changed concurrent with this

	 * code, but in that case another update request will be made and so

	 * the guest will never run with a stale PML value.

	 */

	if (vcpu->kvm->arch.cpu_dirty_logging_count)

	if (atomic_read(&vcpu->kvm->nr_memslots_dirty_logging))

		secondary_exec_controls_setbit(vmx, SECONDARY_EXEC_ENABLE_PML);

	else

		secondary_exec_controls_clearbit(vmx, SECONDARY_EXEC_ENABLE_PML);

arch/x86/kvm/x86.c

+3 −5
Original line number Diff line number Diff line
@@ -12488,16 +12488,14 @@ int kvm_arch_prepare_memory_region(struct kvm *kvm, 


static void kvm_mmu_update_cpu_dirty_logging(struct kvm *kvm, bool enable)

{

	struct kvm_arch *ka = &kvm->arch;

	int nr_slots;



	if (!kvm_x86_ops.cpu_dirty_log_size)

		return;



	if ((enable && ++ka->cpu_dirty_logging_count == 1) ||

	    (!enable && --ka->cpu_dirty_logging_count == 0))

	nr_slots = atomic_read(&kvm->nr_memslots_dirty_logging);

	if ((enable && nr_slots == 1) || !nr_slots)

		kvm_make_all_cpus_request(kvm, KVM_REQ_UPDATE_CPU_DIRTY_LOGGING);



	WARN_ON_ONCE(ka->cpu_dirty_logging_count < 0);

}



static void kvm_mmu_slot_apply_flags(struct kvm *kvm,