| Message ID | 20230616032311.19137-4-tao1.su@linux.intel.com (mailing list archive) |
|---|---|
| State | New, archived |
| Headers | show |
| Series | Add new CPU model EmeraldRapids and GraniteRapids | expand |
On Fri, 16 Jun 2023 11:23:07 +0800 Tao Su <tao1.su@linux.intel.com> wrote: > MCDT_NO bit indicates HW contains the security fix and doesn't need to > be mitigated to avoid data-dependent behaviour for certain instructions. > It needs no hypervisor support. Treat it as supported regardless of what > KVM reports. > > Signed-off-by: Tao Su <tao1.su@linux.intel.com> > Reviewed-by: Xiaoyao Li <xiaoyao.li@intel.com> > --- > target/i386/kvm/kvm.c | 5 +++++ > 1 file changed, 5 insertions(+) > > diff --git a/target/i386/kvm/kvm.c b/target/i386/kvm/kvm.c > index de531842f6..4defd8b479 100644 > --- a/target/i386/kvm/kvm.c > +++ b/target/i386/kvm/kvm.c > @@ -432,6 +432,11 @@ uint32_t kvm_arch_get_supported_cpuid(KVMState *s, uint32_t function, > uint32_t eax; > host_cpuid(7, 1, &eax, &unused, &unused, &unused); > ret |= eax & (CPUID_7_1_EAX_FZRM | CPUID_7_1_EAX_FSRS | CPUID_7_1_EAX_FSRC); > + } else if (function == 7 && index == 2 && reg == R_EDX) { > + /* Not new instructions, just an optimization. */ comment doesn't make much sense to me, just drop it or describe what MCDT_NO is/mitigates. > + uint32_t edx; > + host_cpuid(7, 2, &unused, &unused, &unused, &edx); > + ret |= edx & CPUID_7_2_EDX_MCDT_NO; > } else if (function == 0xd && index == 0 && > (reg == R_EAX || reg == R_EDX)) { > /*
On Mon, Jun 26, 2023 at 03:03:12PM +0200, Igor Mammedov wrote: > On Fri, 16 Jun 2023 11:23:07 +0800 > Tao Su <tao1.su@linux.intel.com> wrote: > > > MCDT_NO bit indicates HW contains the security fix and doesn't need to > > be mitigated to avoid data-dependent behaviour for certain instructions. > > It needs no hypervisor support. Treat it as supported regardless of what > > KVM reports. > > > > Signed-off-by: Tao Su <tao1.su@linux.intel.com> > > Reviewed-by: Xiaoyao Li <xiaoyao.li@intel.com> > > --- > > target/i386/kvm/kvm.c | 5 +++++ > > 1 file changed, 5 insertions(+) > > > > diff --git a/target/i386/kvm/kvm.c b/target/i386/kvm/kvm.c > > index de531842f6..4defd8b479 100644 > > --- a/target/i386/kvm/kvm.c > > +++ b/target/i386/kvm/kvm.c > > @@ -432,6 +432,11 @@ uint32_t kvm_arch_get_supported_cpuid(KVMState *s, uint32_t function, > > uint32_t eax; > > host_cpuid(7, 1, &eax, &unused, &unused, &unused); > > ret |= eax & (CPUID_7_1_EAX_FZRM | CPUID_7_1_EAX_FSRS | CPUID_7_1_EAX_FSRC); > > + } else if (function == 7 && index == 2 && reg == R_EDX) { > > > + /* Not new instructions, just an optimization. */ > comment doesn't make much sense to me, just drop it or > describe what MCDT_NO is/mitigates. Ok, I will drop it in the next version, thanks! > > > + uint32_t edx; > > + host_cpuid(7, 2, &unused, &unused, &unused, &edx); > > + ret |= edx & CPUID_7_2_EDX_MCDT_NO; > > } else if (function == 0xd && index == 0 && > > (reg == R_EAX || reg == R_EDX)) { > > /* > >
diff --git a/target/i386/kvm/kvm.c b/target/i386/kvm/kvm.c index de531842f6..4defd8b479 100644 --- a/target/i386/kvm/kvm.c +++ b/target/i386/kvm/kvm.c @@ -432,6 +432,11 @@ uint32_t kvm_arch_get_supported_cpuid(KVMState *s, uint32_t function, uint32_t eax; host_cpuid(7, 1, &eax, &unused, &unused, &unused); ret |= eax & (CPUID_7_1_EAX_FZRM | CPUID_7_1_EAX_FSRS | CPUID_7_1_EAX_FSRC); + } else if (function == 7 && index == 2 && reg == R_EDX) { + /* Not new instructions, just an optimization. */ + uint32_t edx; + host_cpuid(7, 2, &unused, &unused, &unused, &edx); + ret |= edx & CPUID_7_2_EDX_MCDT_NO; } else if (function == 0xd && index == 0 && (reg == R_EAX || reg == R_EDX)) { /*