Commit 3d4e882e authored by Sean Christopherson's avatar Sean Christopherson
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KVM: SEV: Move init of SNP guest state into sev_init_vmcb() 



Move the initialization of SNP guest state from svm_vcpu_reset() into
sev_init_vmcb() to reduce the number of paths that deal with INIT/RESET
for SEV+ vCPUs from 4+ to 1.  Plumb in @init_event as necessary.

Opportunistically check for an SNP guest outside of
sev_snp_init_protected_guest_state() so that sev_init_vmcb() is consistent
with respect to checking for SEV-ES+ and SNP+ guests.

No functional change intended.

Reviewed-by: default avatarNikunj A Dadhania <nikunj@amd.com>
Link: https://lore.kernel.org/r/20250819234833.3080255-6-seanjc@google.com


Signed-off-by: default avatarSean Christopherson <seanjc@google.com>
parent 34bd82aa

arch/x86/kvm/svm/sev.c

+9 −7
Original line number Diff line number Diff line
@@ -1975,7 +1975,7 @@ static void sev_migrate_from(struct kvm *dst_kvm, struct kvm *src_kvm) 
	kvm_for_each_vcpu(i, dst_vcpu, dst_kvm) {

		dst_svm = to_svm(dst_vcpu);



		sev_init_vmcb(dst_svm);

		sev_init_vmcb(dst_svm, false);



		if (!dst->es_active)

			continue;
@@ -3887,7 +3887,7 @@ static int snp_begin_psc(struct vcpu_svm *svm, struct psc_buffer *psc) 
/*

 * Invoked as part of svm_vcpu_reset() processing of an init event.

 */

void sev_snp_init_protected_guest_state(struct kvm_vcpu *vcpu)

static void sev_snp_init_protected_guest_state(struct kvm_vcpu *vcpu)

{

	struct vcpu_svm *svm = to_svm(vcpu);

	struct kvm_memory_slot *slot;
@@ -3895,9 +3895,6 @@ void sev_snp_init_protected_guest_state(struct kvm_vcpu *vcpu) 
	kvm_pfn_t pfn;

	gfn_t gfn;



	if (!sev_snp_guest(vcpu->kvm))

		return;



	guard(mutex)(&svm->sev_es.snp_vmsa_mutex);



	if (!svm->sev_es.snp_ap_waiting_for_reset)
@@ -4546,8 +4543,10 @@ static void sev_es_init_vmcb(struct vcpu_svm *svm) 
	svm_clr_intercept(svm, INTERCEPT_XSETBV);

}



void sev_init_vmcb(struct vcpu_svm *svm)

void sev_init_vmcb(struct vcpu_svm *svm, bool init_event)

{

	struct kvm_vcpu *vcpu = &svm->vcpu;



	svm->vmcb->control.nested_ctl |= SVM_NESTED_CTL_SEV_ENABLE;

	clr_exception_intercept(svm, UD_VECTOR);
@@ -4557,7 +4556,10 @@ void sev_init_vmcb(struct vcpu_svm *svm) 
	 */

	clr_exception_intercept(svm, GP_VECTOR);



	if (sev_es_guest(svm->vcpu.kvm))

	if (init_event && sev_snp_guest(vcpu->kvm))

		sev_snp_init_protected_guest_state(vcpu);



	if (sev_es_guest(vcpu->kvm))

		sev_es_init_vmcb(svm);

}

arch/x86/kvm/svm/svm.c

+3 −6
Original line number Diff line number Diff line
@@ -1083,7 +1083,7 @@ static void svm_recalc_intercepts_after_set_cpuid(struct kvm_vcpu *vcpu) 
	svm_recalc_msr_intercepts(vcpu);

}



static void init_vmcb(struct kvm_vcpu *vcpu)

static void init_vmcb(struct kvm_vcpu *vcpu, bool init_event)

{

	struct vcpu_svm *svm = to_svm(vcpu);

	struct vmcb *vmcb = svm->vmcb01.ptr;
@@ -1221,7 +1221,7 @@ static void init_vmcb(struct kvm_vcpu *vcpu) 
		svm_set_intercept(svm, INTERCEPT_BUSLOCK);



	if (sev_guest(vcpu->kvm))

		sev_init_vmcb(svm);

		sev_init_vmcb(svm, init_event);



	svm_hv_init_vmcb(vmcb);
@@ -1256,10 +1256,7 @@ static void svm_vcpu_reset(struct kvm_vcpu *vcpu, bool init_event) 
	svm->spec_ctrl = 0;

	svm->virt_spec_ctrl = 0;



	if (init_event)

		sev_snp_init_protected_guest_state(vcpu);



	init_vmcb(vcpu);

	init_vmcb(vcpu, init_event);



	if (!init_event)

		__svm_vcpu_reset(vcpu);

arch/x86/kvm/svm/svm.h

+1 −3
Original line number Diff line number Diff line
@@ -826,7 +826,7 @@ void avic_refresh_virtual_apic_mode(struct kvm_vcpu *vcpu); 
/* sev.c */



int pre_sev_run(struct vcpu_svm *svm, int cpu);

void sev_init_vmcb(struct vcpu_svm *svm);

void sev_init_vmcb(struct vcpu_svm *svm, bool init_event);

void sev_vcpu_after_set_cpuid(struct vcpu_svm *svm);

int sev_es_string_io(struct vcpu_svm *svm, int size, unsigned int port, int in);

void sev_es_vcpu_reset(struct vcpu_svm *svm);
@@ -864,7 +864,6 @@ int sev_cpu_init(struct svm_cpu_data *sd); 
int sev_dev_get_attr(u32 group, u64 attr, u64 *val);

extern unsigned int max_sev_asid;

void sev_handle_rmp_fault(struct kvm_vcpu *vcpu, gpa_t gpa, u64 error_code);

void sev_snp_init_protected_guest_state(struct kvm_vcpu *vcpu);

int sev_gmem_prepare(struct kvm *kvm, kvm_pfn_t pfn, gfn_t gfn, int max_order);

void sev_gmem_invalidate(kvm_pfn_t start, kvm_pfn_t end);

int sev_private_max_mapping_level(struct kvm *kvm, kvm_pfn_t pfn);
@@ -891,7 +890,6 @@ static inline int sev_cpu_init(struct svm_cpu_data *sd) { return 0; } 
static inline int sev_dev_get_attr(u32 group, u64 attr, u64 *val) { return -ENXIO; }

#define max_sev_asid 0

static inline void sev_handle_rmp_fault(struct kvm_vcpu *vcpu, gpa_t gpa, u64 error_code) {}

static inline void sev_snp_init_protected_guest_state(struct kvm_vcpu *vcpu) {}

static inline int sev_gmem_prepare(struct kvm *kvm, kvm_pfn_t pfn, gfn_t gfn, int max_order)

{

	return 0;