From 71d0d497f23c2f73e854e39456f844d77ef85f0b Mon Sep 17 00:00:00 2001 From: Marc Zyngier Date: Thu, 21 Oct 2021 14:10:35 +0100 Subject: [PATCH] FROMGIT: KVM: arm64: Introduce flag shadowing TIF_FOREIGN_FPSTATE We currently have to maintain a mapping the thread_info structure at EL2 in order to be able to check the TIF_FOREIGN_FPSTATE flag. In order to eventually get rid of this, start with a vcpu flag that shadows the thread flag on each entry into the hypervisor. Reviewed-by: Mark Brown Signed-off-by: Marc Zyngier (cherry picked from commit af9a0e21d817f40595aa629de32d3bd96582abef git://git.kernel.org/pub/scm/linux/kernel/git/kvmarm/kvmarm.git next) Bug: 209777660 Signed-off-by: Will Deacon Change-Id: I3a59991de7eca3a08fc3de9ddb11213d889165b5 --- arch/arm64/include/asm/kvm_host.h | 2 ++ arch/arm64/kvm/arm.c | 1 + arch/arm64/kvm/fpsimd.c | 8 ++++++++ arch/arm64/kvm/hyp/include/hyp/switch.h | 2 +- 4 files changed, 12 insertions(+), 1 deletion(-) diff --git a/arch/arm64/include/asm/kvm_host.h b/arch/arm64/include/asm/kvm_host.h index a3cf4ad3be61..d8ae8bc3466f 100644 --- a/arch/arm64/include/asm/kvm_host.h +++ b/arch/arm64/include/asm/kvm_host.h @@ -441,6 +441,7 @@ struct kvm_vcpu_arch { #define KVM_ARM64_DEBUG_STATE_SAVE_SPE (1 << 12) /* Save SPE context if active */ #define KVM_ARM64_DEBUG_STATE_SAVE_TRBE (1 << 13) /* Save TRBE context if active */ +#define KVM_ARM64_FP_FOREIGN_FPSTATE (1 << 14) #define KVM_GUESTDBG_VALID_MASK (KVM_GUESTDBG_ENABLE | \ KVM_GUESTDBG_USE_SW_BP | \ @@ -736,6 +737,7 @@ long kvm_vm_ioctl_mte_copy_tags(struct kvm *kvm, /* Guest/host FPSIMD coordination helpers */ int kvm_arch_vcpu_run_map_fp(struct kvm_vcpu *vcpu); void kvm_arch_vcpu_load_fp(struct kvm_vcpu *vcpu); +void kvm_arch_vcpu_ctxflush_fp(struct kvm_vcpu *vcpu); void kvm_arch_vcpu_ctxsync_fp(struct kvm_vcpu *vcpu); void kvm_arch_vcpu_put_fp(struct kvm_vcpu *vcpu); diff --git a/arch/arm64/kvm/arm.c b/arch/arm64/kvm/arm.c index 126c1eb4e853..ab2bb58e044d 100644 --- a/arch/arm64/kvm/arm.c +++ b/arch/arm64/kvm/arm.c @@ -857,6 +857,7 @@ int kvm_arch_vcpu_ioctl_run(struct kvm_vcpu *vcpu) } kvm_arm_setup_debug(vcpu); + kvm_arch_vcpu_ctxflush_fp(vcpu); /************************************************************** * Enter the guest diff --git a/arch/arm64/kvm/fpsimd.c b/arch/arm64/kvm/fpsimd.c index 2d15e1d6e214..a18b9c1744d5 100644 --- a/arch/arm64/kvm/fpsimd.c +++ b/arch/arm64/kvm/fpsimd.c @@ -79,6 +79,14 @@ void kvm_arch_vcpu_load_fp(struct kvm_vcpu *vcpu) vcpu->arch.flags |= KVM_ARM64_HOST_SVE_ENABLED; } +void kvm_arch_vcpu_ctxflush_fp(struct kvm_vcpu *vcpu) +{ + if (test_thread_flag(TIF_FOREIGN_FPSTATE)) + vcpu->arch.flags |= KVM_ARM64_FP_FOREIGN_FPSTATE; + else + vcpu->arch.flags &= ~KVM_ARM64_FP_FOREIGN_FPSTATE; +} + /* * If the guest FPSIMD state was loaded, update the host's context * tracking data mark the CPU FPSIMD regs as dirty and belonging to vcpu diff --git a/arch/arm64/kvm/hyp/include/hyp/switch.h b/arch/arm64/kvm/hyp/include/hyp/switch.h index 5fd4fad5a5a3..da64daa6f907 100644 --- a/arch/arm64/kvm/hyp/include/hyp/switch.h +++ b/arch/arm64/kvm/hyp/include/hyp/switch.h @@ -45,7 +45,7 @@ static inline bool update_fp_enabled(struct kvm_vcpu *vcpu) * trap the accesses. */ if (!system_supports_fpsimd() || - vcpu->arch.host_thread_info->flags & _TIF_FOREIGN_FPSTATE) + vcpu->arch.flags & KVM_ARM64_FP_FOREIGN_FPSTATE) vcpu->arch.flags &= ~(KVM_ARM64_FP_ENABLED | KVM_ARM64_FP_HOST);