Minki/linux
1
0
Fork 1
mirror of https://github.com/torvalds/linux.git synced 2024-11-26 14:12:06 +00:00
Code Issues Packages Projects Releases Wiki Activity

KVM SVM changes for 6.8:

Browse Source 
- Revert a bogus, made-up nested SVM consistency check for TLB_CONTROL.
 
  - Advertise flush-by-ASID support for nSVM unconditionally, as KVM always
    flushes on nested transitions, i.e. always satisfies flush requests.  This
    allows running bleeding edge versions of VMware Workstation on top of KVM.
 
  - Sanity check that the CPU supports flush-by-ASID when enabling SEV support.
 
  - Fix a benign NMI virtualization bug where KVM would unnecessarily intercept
    IRET when manually injecting an NMI, e.g. when KVM pends an NMI and injects
    a second, "simultaneous" NMI.
 -----BEGIN PGP SIGNATURE-----
 
 iQJGBAABCgAwFiEEMHr+pfEFOIzK+KY1YJEiAU0MEvkFAmWW/9ESHHNlYW5qY0Bn
 b29nbGUuY29tAAoJEGCRIgFNDBL50PcP/Rbdf/68/g1m4JQYl8rf2h7BD4PGE5yw
 ZpeXSkeZmzyRYPiJjJaZLcvvezyusIPoGRfmsKgj2nI7LCSVyHDmaHVp2h854Xz8
 kSWmK5znBYDx+vUqhIKEN2nwFNYSUaSqcRZWvoXi0BzalWlwCgK2yu8xeRDUhn4B
 +gDKlqZuJMYY1J3V8e64ZkvdxRHsw0WyvD0Ns4EgCe/2v5V9gc08a7vuSq80EtaE
 yf0cZmubDwuV96LfZnDkZnZpm4C1GNeLxAN1wlj7J6fAvrCAggetDtkJtWCd8yd0
 0ZtfjBOMVsCDWQsYXbwGGKdeynzATxc354k6yHBIO863z+M5MtEMKlFNCclrakMO
 RHfofZHhL+hn3ACESJPcse3ei0VbV28cL2NFdstUEukvZQoacIH9fz7+1GuWqBpv
 Vb9UJDde029HHsGf+n8LtfQsqV7/8aLV+/4bpiPOHQU+tzAJVxni/H9nJ+7V0lxd
 NfhWME1lEsQWxpBpcXcVB7D7+ri1Wd9eB4IR9xc/VqgLE1Nj4kIZqtOJF9lbY3wk
 +H/Ze/MNNg6E9yIErSIv7sWdrvoOPYWZdGCT8Fhm4OILAsDEO96z7WoVF0eWCdJ1
 xDIFGXNFuyIpVOqk/JZE/Lv5U1C4xhyFQCmk6gXDgepnTn4d8gx3S79iUfXD32gE
 GqAjV9Wwmz+o
 =mXEf
 -----END PGP SIGNATURE-----

Merge tag 'kvm-x86-svm-6.8' of https://github.com/kvm-x86/linux into HEAD

KVM SVM changes for 6.8:

 - Revert a bogus, made-up nested SVM consistency check for TLB_CONTROL.

 - Advertise flush-by-ASID support for nSVM unconditionally, as KVM always
   flushes on nested transitions, i.e. always satisfies flush requests.  This
   allows running bleeding edge versions of VMware Workstation on top of KVM.

 - Sanity check that the CPU supports flush-by-ASID when enabling SEV support.

 - Fix a benign NMI virtualization bug where KVM would unnecessarily intercept
   IRET when manually injecting an NMI, e.g. when KVM pends an NMI and injects
   a second, "simultaneous" NMI.
This commit is contained in:
Paolo Bonzini 2024-01-08 08:10:16 -05:00
commit 8c9244af4d
3 changed files with 21 additions and 19 deletions
Show Stats Download Patch File Download Diff File Expand all files Collapse all files

15
arch/x86/kvm/svm/nested.c
View File

@ -253,18 +253,6 @@ static bool nested_svm_check_bitmap_pa(struct kvm_vcpu *vcpu, u64 pa, u32 size)
kvm_vcpu_is_legal_gpa(vcpu, addr + size - 1);
}
static bool nested_svm_check_tlb_ctl(struct kvm_vcpu *vcpu, u8 tlb_ctl)
{
/* Nested FLUSHBYASID is not supported yet. */
switch(tlb_ctl) {
case TLB_CONTROL_DO_NOTHING:
case TLB_CONTROL_FLUSH_ALL_ASID:
return true;
default:
return false;
}
}
static bool __nested_vmcb_check_controls(struct kvm_vcpu *vcpu,
struct vmcb_ctrl_area_cached *control)
{
@ -284,9 +272,6 @@ static bool __nested_vmcb_check_controls(struct kvm_vcpu *vcpu,
IOPM_SIZE)))
return false;
if (CC(!nested_svm_check_tlb_ctl(vcpu, control->tlb_ctl)))
return false;
if (CC((control->int_ctl & V_NMI_ENABLE_MASK) &&
!vmcb12_is_intercept(control, INTERCEPT_NMI))) {
return false;

7
arch/x86/kvm/svm/sev.c
View File

@ -2191,10 +2191,13 @@ void __init sev_hardware_setup(void)
/*
* SEV must obviously be supported in hardware. Sanity check that the
* CPU supports decode assists, which is mandatory for SEV guests to
* support instruction emulation.
* support instruction emulation. Ditto for flushing by ASID, as SEV
* guests are bound to a single ASID, i.e. KVM can't rotate to a new
* ASID to effect a TLB flush.
*/
if (!boot_cpu_has(X86_FEATURE_SEV) ||
WARN_ON_ONCE(!boot_cpu_has(X86_FEATURE_DECODEASSISTS)))
WARN_ON_ONCE(!boot_cpu_has(X86_FEATURE_DECODEASSISTS)) ||
WARN_ON_ONCE(!boot_cpu_has(X86_FEATURE_FLUSHBYASID)))
goto out;
/* Retrieve SEV CPUID information */

18
arch/x86/kvm/svm/svm.c
View File

@ -3563,8 +3563,15 @@ static void svm_inject_nmi(struct kvm_vcpu *vcpu)
if (svm->nmi_l1_to_l2)
return;
svm->nmi_masked = true;
svm_set_iret_intercept(svm);
/*
* No need to manually track NMI masking when vNMI is enabled, hardware
* automatically sets V_NMI_BLOCKING_MASK as appropriate, including the
* case where software directly injects an NMI.
*/
if (!is_vnmi_enabled(svm)) {
svm->nmi_masked = true;
svm_set_iret_intercept(svm);
}
++vcpu->stat.nmi_injections;
}
@ -5079,6 +5086,13 @@ static __init void svm_set_cpu_caps(void)
kvm_cpu_cap_set(X86_FEATURE_SVM);
kvm_cpu_cap_set(X86_FEATURE_VMCBCLEAN);
/*
* KVM currently flushes TLBs on *every* nested SVM transition,
* and so for all intents and purposes KVM supports flushing by
* ASID, i.e. KVM is guaranteed to honor every L1 ASID flush.
*/
kvm_cpu_cap_set(X86_FEATURE_FLUSHBYASID);
if (nrips)
kvm_cpu_cap_set(X86_FEATURE_NRIPS);