Commit 41d6028e authored by Fuad Tabba's avatar Fuad Tabba Committed by Marc Zyngier
Browse files

KVM: arm64: Convert the SVE guest vcpu flag to a vm flag 



The vcpu flag GUEST_HAS_SVE is per-vcpu, but it is based on what
is now a per-vm feature. Make the flag per-vm.

Signed-off-by: default avatarFuad Tabba <tabba@google.com>
Link: https://lore.kernel.org/r/20241216105057.579031-17-tabba@google.com


Signed-off-by: default avatarMarc Zyngier <maz@kernel.org>
parent c5c17635

arch/arm64/include/asm/kvm_emulate.h

+9 −3
Original line number Diff line number Diff line
@@ -620,7 +620,7 @@ static __always_inline void kvm_write_cptr_el2(u64 val) 
}



/* Resets the value of cptr_el2 when returning to the host. */

static __always_inline void kvm_reset_cptr_el2(struct kvm_vcpu *vcpu)

static __always_inline void __kvm_reset_cptr_el2(struct kvm *kvm)

{

	u64 val;
@@ -631,14 +631,14 @@ static __always_inline void kvm_reset_cptr_el2(struct kvm_vcpu *vcpu) 
	} else if (has_hvhe()) {

		val = CPACR_ELx_FPEN;



		if (!vcpu_has_sve(vcpu) || !guest_owns_fp_regs())

		if (!kvm_has_sve(kvm) || !guest_owns_fp_regs())

			val |= CPACR_ELx_ZEN;

		if (cpus_have_final_cap(ARM64_SME))

			val |= CPACR_ELx_SMEN;

	} else {

		val = CPTR_NVHE_EL2_RES1;



		if (vcpu_has_sve(vcpu) && guest_owns_fp_regs())

		if (kvm_has_sve(kvm) && guest_owns_fp_regs())

			val |= CPTR_EL2_TZ;

		if (!cpus_have_final_cap(ARM64_SME))

			val |= CPTR_EL2_TSM;
@@ -647,6 +647,12 @@ static __always_inline void kvm_reset_cptr_el2(struct kvm_vcpu *vcpu) 
	kvm_write_cptr_el2(val);

}



#ifdef __KVM_NVHE_HYPERVISOR__

#define kvm_reset_cptr_el2(v)	__kvm_reset_cptr_el2(kern_hyp_va((v)->kvm))

#else

#define kvm_reset_cptr_el2(v)	__kvm_reset_cptr_el2((v)->kvm)

#endif



/*

 * Returns a 'sanitised' view of CPTR_EL2, translating from nVHE to the VHE

 * format if E2H isn't set.

arch/arm64/include/asm/kvm_host.h

+12 −6
Original line number Diff line number Diff line
@@ -331,6 +331,8 @@ struct kvm_arch { 
#define KVM_ARCH_FLAG_ID_REGS_INITIALIZED		7

	/* Fine-Grained UNDEF initialised */

#define KVM_ARCH_FLAG_FGU_INITIALIZED			8

	/* SVE exposed to guest */

#define KVM_ARCH_FLAG_GUEST_HAS_SVE			9

	unsigned long flags;



	/* VM-wide vCPU feature set */
@@ -862,12 +864,10 @@ struct kvm_vcpu_arch { 
#define vcpu_set_flag(v, ...)	__vcpu_set_flag((v), __VA_ARGS__)

#define vcpu_clear_flag(v, ...)	__vcpu_clear_flag((v), __VA_ARGS__)



/* SVE exposed to guest */

#define GUEST_HAS_SVE		__vcpu_single_flag(cflags, BIT(0))

/* KVM_ARM_VCPU_INIT completed */

#define VCPU_INITIALIZED	__vcpu_single_flag(cflags, BIT(0))

/* SVE config completed */

#define VCPU_SVE_FINALIZED	__vcpu_single_flag(cflags, BIT(1))

/* KVM_ARM_VCPU_INIT completed */

#define VCPU_INITIALIZED	__vcpu_single_flag(cflags, BIT(2))



/* Exception pending */

#define PENDING_EXCEPTION	__vcpu_single_flag(iflags, BIT(0))
@@ -956,8 +956,14 @@ struct kvm_vcpu_arch { 
				 KVM_GUESTDBG_USE_HW | \

				 KVM_GUESTDBG_SINGLESTEP)



#define vcpu_has_sve(vcpu) (system_supports_sve() &&			\

			    vcpu_get_flag(vcpu, GUEST_HAS_SVE))

#define kvm_has_sve(kvm)	(system_supports_sve() &&		\

				 test_bit(KVM_ARCH_FLAG_GUEST_HAS_SVE, &(kvm)->arch.flags))



#ifdef __KVM_NVHE_HYPERVISOR__

#define vcpu_has_sve(vcpu)	kvm_has_sve(kern_hyp_va((vcpu)->kvm))

#else

#define vcpu_has_sve(vcpu)	kvm_has_sve((vcpu)->kvm)

#endif



#ifdef CONFIG_ARM64_PTR_AUTH

#define vcpu_has_ptrauth(vcpu)						\

arch/arm64/kvm/hyp/nvhe/pkvm.c

+7 −4
Original line number Diff line number Diff line
@@ -248,10 +248,13 @@ void pkvm_put_hyp_vcpu(struct pkvm_hyp_vcpu *hyp_vcpu) 
static void pkvm_init_features_from_host(struct pkvm_hyp_vm *hyp_vm, const struct kvm *host_kvm)

{

	struct kvm *kvm = &hyp_vm->kvm;

	unsigned long host_arch_flags = READ_ONCE(host_kvm->arch.flags);

	DECLARE_BITMAP(allowed_features, KVM_VCPU_MAX_FEATURES);



	/* No restrictions for non-protected VMs. */

	if (!kvm_vm_is_protected(kvm)) {

		hyp_vm->kvm.arch.flags = host_arch_flags;



		bitmap_copy(kvm->arch.vcpu_features,

			    host_kvm->arch.vcpu_features,

			    KVM_VCPU_MAX_FEATURES);
@@ -271,8 +274,10 @@ static void pkvm_init_features_from_host(struct pkvm_hyp_vm *hyp_vm, const struc 
	if (kvm_pvm_ext_allowed(KVM_CAP_ARM_PTRAUTH_GENERIC))

		set_bit(KVM_ARM_VCPU_PTRAUTH_GENERIC, allowed_features);



	if (kvm_pvm_ext_allowed(KVM_CAP_ARM_SVE))

	if (kvm_pvm_ext_allowed(KVM_CAP_ARM_SVE)) {

		set_bit(KVM_ARM_VCPU_SVE, allowed_features);

		kvm->arch.flags |= host_arch_flags & BIT(KVM_ARCH_FLAG_GUEST_HAS_SVE);

	}



	bitmap_and(kvm->arch.vcpu_features, host_kvm->arch.vcpu_features,

		   allowed_features, KVM_VCPU_MAX_FEATURES);
@@ -308,11 +313,9 @@ static void pkvm_vcpu_init_sve(struct pkvm_hyp_vcpu *hyp_vcpu, struct kvm_vcpu * 
{

	struct kvm_vcpu *vcpu = &hyp_vcpu->vcpu;



	if (!vcpu_has_feature(vcpu, KVM_ARM_VCPU_SVE)) {

		vcpu_clear_flag(vcpu, GUEST_HAS_SVE);

	if (!vcpu_has_feature(vcpu, KVM_ARM_VCPU_SVE))

		vcpu_clear_flag(vcpu, VCPU_SVE_FINALIZED);

}

}



static int init_pkvm_hyp_vcpu(struct pkvm_hyp_vcpu *hyp_vcpu,

			      struct pkvm_hyp_vm *hyp_vm,

arch/arm64/kvm/reset.c

+1 −1
Original line number Diff line number Diff line
@@ -85,7 +85,7 @@ static void kvm_vcpu_enable_sve(struct kvm_vcpu *vcpu) 
	 * KVM_REG_ARM64_SVE_VLS.  Allocation is deferred until

	 * kvm_arm_vcpu_finalize(), which freezes the configuration.

	 */

	vcpu_set_flag(vcpu, GUEST_HAS_SVE);

	set_bit(KVM_ARCH_FLAG_GUEST_HAS_SVE, &vcpu->kvm->arch.flags);

}



/*