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Diffstat (limited to 'arch/arm64/kvm/fpsimd.c')
-rw-r--r--arch/arm64/kvm/fpsimd.c36
1 files changed, 27 insertions, 9 deletions
diff --git a/arch/arm64/kvm/fpsimd.c b/arch/arm64/kvm/fpsimd.c
index dc6ecfa5a2d2..aac7808ce216 100644
--- a/arch/arm64/kvm/fpsimd.c
+++ b/arch/arm64/kvm/fpsimd.c
@@ -5,13 +5,14 @@
* Copyright 2018 Arm Limited
* Author: Dave Martin <Dave.Martin@arm.com>
*/
-#include <linux/bottom_half.h>
+#include <linux/irqflags.h>
#include <linux/sched.h>
#include <linux/thread_info.h>
#include <linux/kvm_host.h>
#include <asm/kvm_asm.h>
#include <asm/kvm_host.h>
#include <asm/kvm_mmu.h>
+#include <asm/sysreg.h>
/*
* Called on entry to KVM_RUN unless this vcpu previously ran at least
@@ -61,10 +62,16 @@ void kvm_arch_vcpu_load_fp(struct kvm_vcpu *vcpu)
{
BUG_ON(!current->mm);
- vcpu->arch.flags &= ~(KVM_ARM64_FP_ENABLED | KVM_ARM64_HOST_SVE_IN_USE);
+ vcpu->arch.flags &= ~(KVM_ARM64_FP_ENABLED |
+ KVM_ARM64_HOST_SVE_IN_USE |
+ KVM_ARM64_HOST_SVE_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;
}
/*
@@ -92,19 +99,30 @@ void kvm_arch_vcpu_ctxsync_fp(struct kvm_vcpu *vcpu)
*/
void kvm_arch_vcpu_put_fp(struct kvm_vcpu *vcpu)
{
- local_bh_disable();
+ unsigned long flags;
- update_thread_flag(TIF_SVE,
- vcpu->arch.flags & KVM_ARM64_HOST_SVE_IN_USE);
+ local_irq_save(flags);
if (vcpu->arch.flags & KVM_ARM64_FP_ENABLED) {
/* Clean guest FP state to memory and invalidate cpu view */
fpsimd_save();
fpsimd_flush_cpu_state();
- } else if (!test_thread_flag(TIF_FOREIGN_FPSTATE)) {
- /* Ensure user trap controls are correctly restored */
- fpsimd_bind_task_to_cpu();
+ } else if (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
+ * reset to CPACR_EL1_DEFAULT by the Hyp code, disabling SVE
+ * for EL0. To avoid spurious traps, restore the trap state
+ * seen by kvm_arch_vcpu_load_fp():
+ */
+ if (vcpu->arch.flags & KVM_ARM64_HOST_SVE_ENABLED)
+ sysreg_clear_set(CPACR_EL1, 0, CPACR_EL1_ZEN_EL0EN);
+ else
+ sysreg_clear_set(CPACR_EL1, CPACR_EL1_ZEN_EL0EN, 0);
}
- local_bh_enable();
+ update_thread_flag(TIF_SVE,
+ vcpu->arch.flags & KVM_ARM64_HOST_SVE_IN_USE);
+
+ local_irq_restore(flags);
}