From ec3efc04a6cee45ba5451950253de468d6297a52 Mon Sep 17 00:00:00 2001 From: Fuad Tabba Date: Tue, 8 Apr 2025 19:10:05 +0100 Subject: [PATCH] KVM: arm64: Calculate cptr_el2 traps on activating traps [ Upstream commit 2fd5b4b0e7b440602455b79977bfa64dea101e6c ] Similar to VHE, calculate the value of cptr_el2 from scratch on activate traps. This removes the need to store cptr_el2 in every vcpu structure. Moreover, some traps, such as whether the guest owns the fp registers, need to be set on every vcpu run. Reported-by: James Clark Fixes: 5294afdbf45a ("KVM: arm64: Exclude FP ownership from kvm_vcpu_arch") Signed-off-by: Fuad Tabba Link: https://lore.kernel.org/r/20241216105057.579031-13-tabba@google.com Signed-off-by: Marc Zyngier Signed-off-by: Mark Brown Signed-off-by: Greg Kroah-Hartman --- arch/arm64/include/asm/kvm_host.h | 1 - arch/arm64/kvm/arm.c | 1 - arch/arm64/kvm/hyp/nvhe/switch.c | 35 +++++++++++++++++++++++-------- 3 files changed, 26 insertions(+), 11 deletions(-) diff --git a/arch/arm64/include/asm/kvm_host.h b/arch/arm64/include/asm/kvm_host.h index 3d4e2396a2d7f..2e0952134e2e1 100644 --- a/arch/arm64/include/asm/kvm_host.h +++ b/arch/arm64/include/asm/kvm_host.h @@ -301,7 +301,6 @@ struct kvm_vcpu_arch { /* Values of trap registers for the guest. */ u64 hcr_el2; u64 mdcr_el2; - u64 cptr_el2; /* Values of trap registers for the host before guest entry. */ u64 mdcr_el2_host; diff --git a/arch/arm64/kvm/arm.c b/arch/arm64/kvm/arm.c index 9ded5443de487..5ca8782edb960 100644 --- a/arch/arm64/kvm/arm.c +++ b/arch/arm64/kvm/arm.c @@ -1138,7 +1138,6 @@ static int kvm_arch_vcpu_ioctl_vcpu_init(struct kvm_vcpu *vcpu, } vcpu_reset_hcr(vcpu); - vcpu->arch.cptr_el2 = CPTR_EL2_DEFAULT; /* * Handle the "start in power-off" case. diff --git a/arch/arm64/kvm/hyp/nvhe/switch.c b/arch/arm64/kvm/hyp/nvhe/switch.c index 4db5409f40c4f..c0885197f2a55 100644 --- a/arch/arm64/kvm/hyp/nvhe/switch.c +++ b/arch/arm64/kvm/hyp/nvhe/switch.c @@ -34,21 +34,38 @@ DEFINE_PER_CPU(struct kvm_host_data, kvm_host_data); DEFINE_PER_CPU(struct kvm_cpu_context, kvm_hyp_ctxt); DEFINE_PER_CPU(unsigned long, kvm_hyp_vector); -static void __activate_traps(struct kvm_vcpu *vcpu) +static bool guest_owns_fp_regs(struct kvm_vcpu *vcpu) { - u64 val; + return vcpu->arch.flags & KVM_ARM64_FP_ENABLED; +} - ___activate_traps(vcpu); - __activate_traps_common(vcpu); +static void __activate_cptr_traps(struct kvm_vcpu *vcpu) +{ + u64 val = CPTR_EL2_TAM; /* Same bit irrespective of E2H */ - val = vcpu->arch.cptr_el2; - val |= CPTR_EL2_TTA | CPTR_EL2_TAM; - if (!update_fp_enabled(vcpu)) { - val |= CPTR_EL2_TFP | CPTR_EL2_TZ; - __activate_traps_fpsimd32(vcpu); + /* !hVHE case upstream */ + if (1) { + val |= CPTR_EL2_TTA | CPTR_NVHE_EL2_RES1; + + if (!vcpu_has_sve(vcpu) || !guest_owns_fp_regs(vcpu)) + val |= CPTR_EL2_TZ; + + if (!guest_owns_fp_regs(vcpu)) + val |= CPTR_EL2_TFP; } + if (!guest_owns_fp_regs(vcpu)) + __activate_traps_fpsimd32(vcpu); + write_sysreg(val, cptr_el2); +} + +static void __activate_traps(struct kvm_vcpu *vcpu) +{ + ___activate_traps(vcpu); + __activate_traps_common(vcpu); + __activate_cptr_traps(vcpu); + write_sysreg(__this_cpu_read(kvm_hyp_vector), vbar_el2); if (cpus_have_final_cap(ARM64_WORKAROUND_SPECULATIVE_AT)) { -- 2.47.3