From: Fuad Tabba Date: Wed, 16 Apr 2025 15:26:41 +0000 (+0000) Subject: KVM: arm64: Track SVE state in the hypervisor vcpu structure X-Git-Tag: v6.16-rc1~129^2~2^2~6^2~11^2~6 X-Git-Url: http://git.ipfire.org/?a=commitdiff_plain;h=5db1bef933427aa467ad89c7b695a84a6b4afe16;p=thirdparty%2Flinux.git KVM: arm64: Track SVE state in the hypervisor vcpu structure When dealing with a guest with SVE enabled, make sure the host SVE state is pinned at EL2 S1, and that the hypervisor vCPU state is correctly initialised (and then unpinned on teardown). Co-authored-by: Marc Zyngier Signed-off-by: Fuad Tabba Signed-off-by: Quentin Perret Link: https://lore.kernel.org/r/20250416152648.2982950-2-qperret@google.com Signed-off-by: Marc Zyngier --- diff --git a/arch/arm64/include/asm/kvm_host.h b/arch/arm64/include/asm/kvm_host.h index 08ba91e6fb035..330f3c34a6bd0 100644 --- a/arch/arm64/include/asm/kvm_host.h +++ b/arch/arm64/include/asm/kvm_host.h @@ -971,20 +971,22 @@ struct kvm_vcpu_arch { #define vcpu_sve_zcr_elx(vcpu) \ (unlikely(is_hyp_ctxt(vcpu)) ? ZCR_EL2 : ZCR_EL1) -#define vcpu_sve_state_size(vcpu) ({ \ +#define sve_state_size_from_vl(sve_max_vl) ({ \ size_t __size_ret; \ - unsigned int __vcpu_vq; \ + unsigned int __vq; \ \ - if (WARN_ON(!sve_vl_valid((vcpu)->arch.sve_max_vl))) { \ + if (WARN_ON(!sve_vl_valid(sve_max_vl))) { \ __size_ret = 0; \ } else { \ - __vcpu_vq = vcpu_sve_max_vq(vcpu); \ - __size_ret = SVE_SIG_REGS_SIZE(__vcpu_vq); \ + __vq = sve_vq_from_vl(sve_max_vl); \ + __size_ret = SVE_SIG_REGS_SIZE(__vq); \ } \ \ __size_ret; \ }) +#define vcpu_sve_state_size(vcpu) sve_state_size_from_vl((vcpu)->arch.sve_max_vl) + #define KVM_GUESTDBG_VALID_MASK (KVM_GUESTDBG_ENABLE | \ KVM_GUESTDBG_USE_SW_BP | \ KVM_GUESTDBG_USE_HW | \ diff --git a/arch/arm64/kvm/hyp/nvhe/hyp-main.c b/arch/arm64/kvm/hyp/nvhe/hyp-main.c index 2c37680d954cf..59db9606e6e15 100644 --- a/arch/arm64/kvm/hyp/nvhe/hyp-main.c +++ b/arch/arm64/kvm/hyp/nvhe/hyp-main.c @@ -123,10 +123,6 @@ static void flush_hyp_vcpu(struct pkvm_hyp_vcpu *hyp_vcpu) hyp_vcpu->vcpu.arch.ctxt = host_vcpu->arch.ctxt; - hyp_vcpu->vcpu.arch.sve_state = kern_hyp_va(host_vcpu->arch.sve_state); - /* Limit guest vector length to the maximum supported by the host. */ - hyp_vcpu->vcpu.arch.sve_max_vl = min(host_vcpu->arch.sve_max_vl, kvm_host_sve_max_vl); - hyp_vcpu->vcpu.arch.mdcr_el2 = host_vcpu->arch.mdcr_el2; hyp_vcpu->vcpu.arch.hcr_el2 &= ~(HCR_TWI | HCR_TWE); hyp_vcpu->vcpu.arch.hcr_el2 |= READ_ONCE(host_vcpu->arch.hcr_el2) & diff --git a/arch/arm64/kvm/hyp/nvhe/pkvm.c b/arch/arm64/kvm/hyp/nvhe/pkvm.c index 5a335a51deca1..338505cb0171b 100644 --- a/arch/arm64/kvm/hyp/nvhe/pkvm.c +++ b/arch/arm64/kvm/hyp/nvhe/pkvm.c @@ -372,6 +372,18 @@ static void unpin_host_vcpu(struct kvm_vcpu *host_vcpu) hyp_unpin_shared_mem(host_vcpu, host_vcpu + 1); } +static void unpin_host_sve_state(struct pkvm_hyp_vcpu *hyp_vcpu) +{ + void *sve_state; + + if (!vcpu_has_feature(&hyp_vcpu->vcpu, KVM_ARM_VCPU_SVE)) + return; + + sve_state = kern_hyp_va(hyp_vcpu->vcpu.arch.sve_state); + hyp_unpin_shared_mem(sve_state, + sve_state + vcpu_sve_state_size(&hyp_vcpu->vcpu)); +} + static void unpin_host_vcpus(struct pkvm_hyp_vcpu *hyp_vcpus[], unsigned int nr_vcpus) { @@ -384,6 +396,7 @@ static void unpin_host_vcpus(struct pkvm_hyp_vcpu *hyp_vcpus[], continue; unpin_host_vcpu(hyp_vcpu->host_vcpu); + unpin_host_sve_state(hyp_vcpu); } } @@ -398,12 +411,40 @@ static void init_pkvm_hyp_vm(struct kvm *host_kvm, struct pkvm_hyp_vm *hyp_vm, pkvm_init_features_from_host(hyp_vm, host_kvm); } -static void pkvm_vcpu_init_sve(struct pkvm_hyp_vcpu *hyp_vcpu, struct kvm_vcpu *host_vcpu) +static int pkvm_vcpu_init_sve(struct pkvm_hyp_vcpu *hyp_vcpu, struct kvm_vcpu *host_vcpu) { struct kvm_vcpu *vcpu = &hyp_vcpu->vcpu; + unsigned int sve_max_vl; + size_t sve_state_size; + void *sve_state; + int ret = 0; - if (!vcpu_has_feature(vcpu, KVM_ARM_VCPU_SVE)) + if (!vcpu_has_feature(vcpu, KVM_ARM_VCPU_SVE)) { vcpu_clear_flag(vcpu, VCPU_SVE_FINALIZED); + return 0; + } + + /* Limit guest vector length to the maximum supported by the host. */ + sve_max_vl = min(READ_ONCE(host_vcpu->arch.sve_max_vl), kvm_host_sve_max_vl); + sve_state_size = sve_state_size_from_vl(sve_max_vl); + sve_state = kern_hyp_va(READ_ONCE(host_vcpu->arch.sve_state)); + + if (!sve_state || !sve_state_size) { + ret = -EINVAL; + goto err; + } + + ret = hyp_pin_shared_mem(sve_state, sve_state + sve_state_size); + if (ret) + goto err; + + vcpu->arch.sve_state = sve_state; + vcpu->arch.sve_max_vl = sve_max_vl; + + return 0; +err: + clear_bit(KVM_ARM_VCPU_SVE, vcpu->kvm->arch.vcpu_features); + return ret; } static int init_pkvm_hyp_vcpu(struct pkvm_hyp_vcpu *hyp_vcpu, @@ -432,7 +473,7 @@ static int init_pkvm_hyp_vcpu(struct pkvm_hyp_vcpu *hyp_vcpu, if (ret) goto done; - pkvm_vcpu_init_sve(hyp_vcpu, host_vcpu); + ret = pkvm_vcpu_init_sve(hyp_vcpu, host_vcpu); done: if (ret) unpin_host_vcpu(host_vcpu);