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| author | Paolo Bonzini <pbonzini@redhat.com> | 2019-07-22 13:31:27 +0200 |
|---|---|---|
| committer | Greg Kroah-Hartman <gregkh@linuxfoundation.org> | 2019-07-28 08:28:38 +0200 |
| commit | 644688604559a6db751b9f26dcc8d38b8c439b0e (patch) | |
| tree | 5b1f5b8bf3c2bb4448204ca1ecf9546994714b71 | |
| parent | 79a431342a92c98f96a6a35ffda37b25ab0fecbe (diff) | |
| download | linux-stable-644688604559a6db751b9f26dcc8d38b8c439b0e.tar.gz linux-stable-644688604559a6db751b9f26dcc8d38b8c439b0e.tar.bz2 linux-stable-644688604559a6db751b9f26dcc8d38b8c439b0e.zip | |
Revert "kvm: x86: Use task structs fpu field for user"
commit ec269475cba7bcdd1eb8fdf8e87f4c6c81a376fe upstream.
This reverts commit 240c35a3783ab9b3a0afaba0dde7291295680a6b
("kvm: x86: Use task structs fpu field for user", 2018-11-06).
The commit is broken and causes QEMU's FPU state to be destroyed
when KVM_RUN is preempted.
Fixes: 240c35a3783a ("kvm: x86: Use task structs fpu field for user")
Cc: stable@vger.kernel.org
Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
| -rw-r--r-- | arch/x86/include/asm/kvm_host.h | 7 | ||||
| -rw-r--r-- | arch/x86/kvm/x86.c | 4 |
2 files changed, 6 insertions, 5 deletions
diff --git a/arch/x86/include/asm/kvm_host.h b/arch/x86/include/asm/kvm_host.h index c79abe7ca093..564729a4a25c 100644 --- a/arch/x86/include/asm/kvm_host.h +++ b/arch/x86/include/asm/kvm_host.h @@ -609,15 +609,16 @@ struct kvm_vcpu_arch { /* * QEMU userspace and the guest each have their own FPU state. - * In vcpu_run, we switch between the user, maintained in the - * task_struct struct, and guest FPU contexts. While running a VCPU, - * the VCPU thread will have the guest FPU context. + * In vcpu_run, we switch between the user and guest FPU contexts. + * While running a VCPU, the VCPU thread will have the guest FPU + * context. * * Note that while the PKRU state lives inside the fpu registers, * it is switched out separately at VMENTER and VMEXIT time. The * "guest_fpu" state here contains the guest FPU context, with the * host PRKU bits. */ + struct fpu user_fpu; struct fpu *guest_fpu; u64 xcr0; diff --git a/arch/x86/kvm/x86.c b/arch/x86/kvm/x86.c index 37028ea85d4c..aede8fa2ea9a 100644 --- a/arch/x86/kvm/x86.c +++ b/arch/x86/kvm/x86.c @@ -8172,7 +8172,7 @@ static int complete_emulated_mmio(struct kvm_vcpu *vcpu) static void kvm_load_guest_fpu(struct kvm_vcpu *vcpu) { preempt_disable(); - copy_fpregs_to_fpstate(¤t->thread.fpu); + copy_fpregs_to_fpstate(&vcpu->arch.user_fpu); /* PKRU is separately restored in kvm_x86_ops->run. */ __copy_kernel_to_fpregs(&vcpu->arch.guest_fpu->state, ~XFEATURE_MASK_PKRU); @@ -8185,7 +8185,7 @@ static void kvm_put_guest_fpu(struct kvm_vcpu *vcpu) { preempt_disable(); copy_fpregs_to_fpstate(vcpu->arch.guest_fpu); - copy_kernel_to_fpregs(¤t->thread.fpu.state); + copy_kernel_to_fpregs(&vcpu->arch.user_fpu.state); preempt_enable(); ++vcpu->stat.fpu_reload; trace_kvm_fpu(0); |