KVM: x86: Apply TSX_CTRL_CPUID_CLEAR if and only if the vCPU has RTM or HLE

Browse source

When emulating CPUID, retrieve MSR_IA32_TSX_CTRL.TSX_CTRL_CPUID_CLEAR if
and only if RTM and/or HLE feature bits need to be cleared.  Getting the
MSR value is unnecessary if neither bit is set, and avoiding the lookup
saves ~80 cycles for vCPUs without RTM or HLE.

Cc: Jim Mattson <jmattson@google.com>
Reviewed-by: Jim Mattson <jmattson@google.com>
Link: https://lore.kernel.org/r/20241211013302.1347853-4-seanjc@google.com
Signed-off-by: Sean Christopherson <seanjc@google.com>

...

This commit is contained in:

Sean Christopherson 2024-12-10 17:33:00 -08:00

parent aa93b6f96f

commit 7e9f735e7a

1 changed files with 2 additions and 1 deletions

Show all changes Ignore whitespace when comparing lines Ignore changes in amount of whitespace Ignore changes in whitespace at EOL

Download patch file Download diff file Expand all files Collapse all files

3

arch/x86/kvm/cpuid.c

View file