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author | Marc Zyngier <maz@kernel.org> | 2021-12-01 12:13:44 +0000 |
---|---|---|
committer | Marc Zyngier <maz@kernel.org> | 2021-12-01 12:13:44 +0000 |
commit | 2d761dbf7ff48b7eca4486658c5995b9669bcbbc (patch) | |
tree | 59e673b826de1306d6bf6cc13527da1f7a3790a0 /arch/arm64/kvm/fpsimd.c | |
parent | e525523c198921161d3ba17dfab1bd3aef2ed3bc (diff) | |
parent | 31aa126de88e1e9f562f708a9b0ec5917ba97dce (diff) | |
download | linux-stable-2d761dbf7ff48b7eca4486658c5995b9669bcbbc.tar.gz linux-stable-2d761dbf7ff48b7eca4486658c5995b9669bcbbc.tar.bz2 linux-stable-2d761dbf7ff48b7eca4486658c5995b9669bcbbc.zip |
Merge branch kvm-arm64/fpsimd-tracking into kvmarm-master/next
* kvm-arm64/fpsimd-tracking:
: .
: Simplify the handling of both the FP/SIMD and SVE state by
: removing the need for mapping the thread at EL2, and by
: dropping the tracking of the host's SVE state which is
: always invalid by construction.
: .
arm64/fpsimd: Document the use of TIF_FOREIGN_FPSTATE by KVM
KVM: arm64: Stop mapping current thread_info at EL2
KVM: arm64: Introduce flag shadowing TIF_FOREIGN_FPSTATE
KVM: arm64: Remove unused __sve_save_state
KVM: arm64: Get rid of host SVE tracking/saving
KVM: arm64: Reorder vcpu flag definitions
Signed-off-by: Marc Zyngier <maz@kernel.org>
Diffstat (limited to 'arch/arm64/kvm/fpsimd.c')
-rw-r--r-- | arch/arm64/kvm/fpsimd.c | 46 |
1 files changed, 16 insertions, 30 deletions
diff --git a/arch/arm64/kvm/fpsimd.c b/arch/arm64/kvm/fpsimd.c index 62c0d78da7be..5526d79c7b47 100644 --- a/arch/arm64/kvm/fpsimd.c +++ b/arch/arm64/kvm/fpsimd.c @@ -7,7 +7,6 @@ */ #include <linux/irqflags.h> #include <linux/sched.h> -#include <linux/thread_info.h> #include <linux/kvm_host.h> #include <asm/fpsimd.h> #include <asm/kvm_asm.h> @@ -28,24 +27,13 @@ int kvm_arch_vcpu_run_map_fp(struct kvm_vcpu *vcpu) { int ret; - struct thread_info *ti = ¤t->thread_info; struct user_fpsimd_state *fpsimd = ¤t->thread.uw.fpsimd_state; - /* - * Make sure the host task thread flags and fpsimd state are - * visible to hyp: - */ - ret = create_hyp_mappings(ti, ti + 1, PAGE_HYP); - if (ret) - goto error; - + /* Make sure the host task fpsimd state is visible to hyp: */ ret = create_hyp_mappings(fpsimd, fpsimd + 1, PAGE_HYP); - if (ret) - goto error; + if (!ret) + vcpu->arch.host_fpsimd_state = kern_hyp_va(fpsimd); - vcpu->arch.host_thread_info = kern_hyp_va(ti); - vcpu->arch.host_fpsimd_state = kern_hyp_va(fpsimd); -error: return ret; } @@ -55,26 +43,27 @@ error: * * Here, we just set the correct metadata to indicate that the FPSIMD * state in the cpu regs (if any) belongs to current on the host. - * - * TIF_SVE is backed up here, since it may get clobbered with guest state. - * This flag is restored by kvm_arch_vcpu_put_fp(vcpu). */ void kvm_arch_vcpu_load_fp(struct kvm_vcpu *vcpu) { BUG_ON(!current->mm); + BUG_ON(test_thread_flag(TIF_SVE)); - vcpu->arch.flags &= ~(KVM_ARM64_FP_ENABLED | - KVM_ARM64_HOST_SVE_IN_USE | - KVM_ARM64_HOST_SVE_ENABLED); + vcpu->arch.flags &= ~KVM_ARM64_FP_ENABLED; vcpu->arch.flags |= KVM_ARM64_FP_HOST; - if (test_thread_flag(TIF_SVE)) - vcpu->arch.flags |= KVM_ARM64_HOST_SVE_IN_USE; - if (read_sysreg(cpacr_el1) & CPACR_EL1_ZEN_EL0EN) 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 @@ -104,13 +93,11 @@ void kvm_arch_vcpu_ctxsync_fp(struct kvm_vcpu *vcpu) void kvm_arch_vcpu_put_fp(struct kvm_vcpu *vcpu) { unsigned long flags; - bool host_has_sve = system_supports_sve(); - bool guest_has_sve = vcpu_has_sve(vcpu); local_irq_save(flags); if (vcpu->arch.flags & KVM_ARM64_FP_ENABLED) { - if (guest_has_sve) { + if (vcpu_has_sve(vcpu)) { __vcpu_sys_reg(vcpu, ZCR_EL1) = read_sysreg_el1(SYS_ZCR); /* Restore the VL that was saved when bound to the CPU */ @@ -120,7 +107,7 @@ void kvm_arch_vcpu_put_fp(struct kvm_vcpu *vcpu) } fpsimd_save_and_flush_cpu_state(); - } else if (has_vhe() && host_has_sve) { + } else if (has_vhe() && system_supports_sve()) { /* * The FPSIMD/SVE state in the CPU has not been touched, and we * have SVE (and VHE): CPACR_EL1 (alias CPTR_EL2) has been @@ -134,8 +121,7 @@ void kvm_arch_vcpu_put_fp(struct kvm_vcpu *vcpu) sysreg_clear_set(CPACR_EL1, CPACR_EL1_ZEN_EL0EN, 0); } - update_thread_flag(TIF_SVE, - vcpu->arch.flags & KVM_ARM64_HOST_SVE_IN_USE); + update_thread_flag(TIF_SVE, 0); local_irq_restore(flags); } |