diff options
| author | Thomas Gleixner <tglx@linutronix.de> | 2021-10-22 21:55:53 +0300 |
|---|---|---|
| committer | Borislav Petkov <bp@suse.de> | 2021-10-23 17:13:29 +0300 |
| commit | d69c1382e1b73a0496a70872a035ca2b22d074e5 (patch) | |
| tree | 6db33a2e11b7dbacd73033a238b8fbde93e4b9ab /arch/x86/kvm/svm | |
| parent | 69f6ed1d14c6bcf712f4bb22a231c15eeab401e7 (diff) | |
| download | linux-d69c1382e1b73a0496a70872a035ca2b22d074e5.tar.xz | |
x86/kvm: Convert FPU handling to a single swap buffer
For the upcoming AMX support it's necessary to do a proper integration with
KVM. Currently KVM allocates two FPU structs which are used for saving the user
state of the vCPU thread and restoring the guest state when entering
vcpu_run() and doing the reverse operation before leaving vcpu_run().
With the new fpstate mechanism this can be reduced to one extra buffer by
swapping the fpstate pointer in current::thread::fpu. This makes the
upcoming support for AMX and XFD simpler because then fpstate information
(features, sizes, xfd) are always consistent and it does not require any
nasty workarounds.
Convert the KVM FPU code over to this new scheme.
Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
Signed-off-by: Borislav Petkov <bp@suse.de>
Link: https://lkml.kernel.org/r/20211022185313.019454292@linutronix.de
Diffstat (limited to 'arch/x86/kvm/svm')
| -rw-r--r-- | arch/x86/kvm/svm/svm.c | 7 |
1 files changed, 4 insertions, 3 deletions
diff --git a/arch/x86/kvm/svm/svm.c b/arch/x86/kvm/svm/svm.c index 989685098b3e..f39c87ddc2e5 100644 --- a/arch/x86/kvm/svm/svm.c +++ b/arch/x86/kvm/svm/svm.c @@ -36,6 +36,7 @@ #include <asm/spec-ctrl.h> #include <asm/cpu_device_id.h> #include <asm/traps.h> +#include <asm/fpu/api.h> #include <asm/virtext.h> #include "trace.h" @@ -1346,10 +1347,10 @@ static int svm_create_vcpu(struct kvm_vcpu *vcpu) /* * SEV-ES guests maintain an encrypted version of their FPU * state which is restored and saved on VMRUN and VMEXIT. - * Free the fpu structure to prevent KVM from attempting to - * access the FPU state. + * Mark vcpu->arch.guest_fpu->fpstate as scratch so it won't + * do xsave/xrstor on it. */ - kvm_free_guest_fpu(vcpu); + fpstate_set_confidential(&vcpu->arch.guest_fpu); } err = avic_init_vcpu(svm); |