Messages in this thread | | | Date | Tue, 16 Apr 2024 16:49:42 -0700 | Subject | Re: [PATCH v8 2/2] x86/mm: Don't disable PCID if the kernel is running on a hypervisor | From | Sean Christopherson <> |
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On Sat, Apr 13, 2024, Xi Ruoyao wrote: > The Intel erratum for "incomplete Global INVLPG flushes" says: > > This erratum does not apply in VMX non-root operation. It applies > only when PCIDs are enabled and either in VMX root operation or > outside VMX operation. > > So if the kernel is running in a hypervisor, we are in VMX non-root > operation and we should be safe to use PCID. > > Cc: Dave Hansen <dave.hansen@linux.intel.com> > Cc: Michael Kelley <mhklinux@outlook.com> > Cc: Pawan Gupta <pawan.kumar.gupta@linux.intel.com> > Cc: Sean Christopherson <seanjc@google.com> > Cc: Andrew Cooper <andrew.cooper3@citrix.com> > Link: https://lore.kernel.org/all/168436059559.404.13934972543631851306.tip-bot2@tip-bot2/ > Link: https://cdrdv2.intel.com/v1/dl/getContent/740518 # RPL042, rev. 13 > Link: https://cdrdv2.intel.com/v1/dl/getContent/682436 # ADL063, rev. 24 > Signed-off-by: Xi Ruoyao <xry111@xry111.site> > --- > arch/x86/mm/init.c | 8 ++++++++ > 1 file changed, 8 insertions(+) > > diff --git a/arch/x86/mm/init.c b/arch/x86/mm/init.c > index c318cdc35467..6010f86c5acd 100644 > --- a/arch/x86/mm/init.c > +++ b/arch/x86/mm/init.c > @@ -275,6 +275,14 @@ static void __init probe_page_size_mask(void) > * microcode is not updated to fix the issue. > */ > static const struct x86_cpu_id invlpg_miss_ids[] = { > + /* Only bare-metal is affected. PCIDs in guests are OK. */ > + { > + .vendor = X86_VENDOR_INTEL, > + .family = 6, > + .model = INTEL_FAM6_ANY, > + .feature = X86_FEATURE_HYPERVISOR,
Isn't this inverted? x86_match_cpu() will return NULL if the CPU doesn't have HYPERVISOR. We want it to return NULL if the CPU *does* have HYPERVISOR.
> + .driver_data = 0, > + }, > INTEL_MATCH(INTEL_FAM6_ALDERLAKE, 0x2e), > INTEL_MATCH(INTEL_FAM6_ALDERLAKE_L, 0x42c), > INTEL_MATCH(INTEL_FAM6_ATOM_GRACEMONT, 0x11), > -- > 2.44.0 >
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