diff options
Diffstat (limited to 'arch/arm64/kvm/fpsimd.c')
| -rw-r--r-- | arch/arm64/kvm/fpsimd.c | 79 |
1 files changed, 41 insertions, 38 deletions
diff --git a/arch/arm64/kvm/fpsimd.c b/arch/arm64/kvm/fpsimd.c index 5621020b28de..2f48fd362a8c 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> @@ -15,6 +14,19 @@ #include <asm/kvm_mmu.h> #include <asm/sysreg.h> +void kvm_vcpu_unshare_task_fp(struct kvm_vcpu *vcpu) +{ + struct task_struct *p = vcpu->arch.parent_task; + struct user_fpsimd_state *fpsimd; + + if (!is_protected_kvm_enabled() || !p) + return; + + fpsimd = &p->thread.uw.fpsimd_state; + kvm_unshare_hyp(fpsimd, fpsimd + 1); + put_task_struct(p); +} + /* * Called on entry to KVM_RUN unless this vcpu previously ran at least * once and the most recent prior KVM_RUN for this vcpu was called from @@ -28,36 +40,29 @@ 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; + kvm_vcpu_unshare_task_fp(vcpu); - ret = create_hyp_mappings(fpsimd, fpsimd + 1, PAGE_HYP); + /* Make sure the host task fpsimd state is visible to hyp: */ + ret = kvm_share_hyp(fpsimd, fpsimd + 1); if (ret) - goto error; - - if (vcpu->arch.sve_state) { - void *sve_end; + return ret; - sve_end = vcpu->arch.sve_state + vcpu_sve_state_size(vcpu); + vcpu->arch.host_fpsimd_state = kern_hyp_va(fpsimd); - ret = create_hyp_mappings(vcpu->arch.sve_state, sve_end, - PAGE_HYP); - if (ret) - goto error; + /* + * We need to keep current's task_struct pinned until its data has been + * unshared with the hypervisor to make sure it is not re-used by the + * kernel and donated to someone else while already shared -- see + * kvm_vcpu_unshare_task_fp() for the matching put_task_struct(). + */ + if (is_protected_kvm_enabled()) { + get_task_struct(current); + vcpu->arch.parent_task = current; } - vcpu->arch.host_thread_info = kern_hyp_va(ti); - vcpu->arch.host_fpsimd_state = kern_hyp_va(fpsimd); -error: - return ret; + return 0; } /* @@ -66,26 +71,27 @@ 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 @@ -115,13 +121,11 @@ 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 */ @@ -131,7 +135,7 @@ 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 @@ -145,8 +149,7 @@ 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); } |