mirrors/linux
1
0
Fork 0
mirror of https://git.kernel.org/pub/scm/linux/kernel/git/torvalds/linux.git synced 2026-05-04 10:56:06 -04:00
Code Issues Packages Projects Releases Wiki Activity

KVM: VMX: Pass XFD_ERR as pseudo-payload when injecting #NM

Browse Source 
Pass XFD_ERR via KVM's exception payload mechanism when injecting an #NM
after interception so that XFD_ERR can be propagated to FRED's event_data
field without needing a dedicated field (which would need to be migrated).

For non-FRED vCPUs, this is a glorified NOP as
kvm_deliver_exception_payload() will simply do nothing (which is desirable
and correct).

Signed-off-by: Xin Li (Intel) <xin@zytor.com>
Tested-by: Shan Kang <shan.kang@intel.com>
Link: https://lore.kernel.org/r/20241001050110.3643764-15-xin@zytor.com
Signed-off-by: Sean Christopherson <seanjc@google.com>
This commit is contained in:
Sean Christopherson
2024-09-30 22:00:57 -07:00
parent 3ef0df3f76
commit d62c02af7a
1 changed files with 10 additions and 4 deletions
Download Patch File Download Diff File Expand all files Collapse all files

14
arch/x86/kvm/vmx/vmx.c
View File

@@ -5215,6 +5215,12 @@ bool vmx_guest_inject_ac(struct kvm_vcpu *vcpu)
(kvm_get_rflags(vcpu) & X86_EFLAGS_AC);
}
static bool is_xfd_nm_fault(struct kvm_vcpu *vcpu)
{
return vcpu->arch.guest_fpu.fpstate->xfd &&
!kvm_is_cr0_bit_set(vcpu, X86_CR0_TS);
}
static int handle_exception_nmi(struct kvm_vcpu *vcpu)
{
struct vcpu_vmx *vmx = to_vmx(vcpu);
@@ -5241,7 +5247,8 @@ static int handle_exception_nmi(struct kvm_vcpu *vcpu)
* point.
*/
if (is_nm_fault(intr_info)) {
kvm_queue_exception(vcpu, NM_VECTOR);
kvm_queue_exception_p(vcpu, NM_VECTOR,
is_xfd_nm_fault(vcpu) ? vcpu->arch.guest_fpu.xfd_err : 0);
return 1;
}
@@ -6997,14 +7004,13 @@ static void handle_nm_fault_irqoff(struct kvm_vcpu *vcpu)
*
* Update the guest's XFD_ERR if and only if XFD is enabled, as the #NM
* interception may have been caused by L1 interception. Per the SDM,
* XFD_ERR is not modified if CR0.TS=1.
* XFD_ERR is not modified for non-XFD #NM, i.e. if CR0.TS=1.
*
* Note, XFD_ERR is updated _before_ the #NM interception check, i.e.
* unlike CR2 and DR6, the value is not a payload that is attached to
* the #NM exception.
*/
if (vcpu->arch.guest_fpu.fpstate->xfd &&
!kvm_is_cr0_bit_set(vcpu, X86_CR0_TS))
if (is_xfd_nm_fault(vcpu))
rdmsrl(MSR_IA32_XFD_ERR, vcpu->arch.guest_fpu.xfd_err);
}