LbrExtV2, introduced on Zen 4, is a branch sampling facility providing a 16-entry stack of last-taken branches via dedicated MSRs: * MSR 0xC000010E - Last Branch Stack Select (LBR_SELECT) * MSR 0xC000010F - Debug Extension Control (DBG_EXTN_CFG) * MSR 0xC0010300..0xC001031F - 16 LBR FROM/TO MSR pairs
This QEMU series exposes AMD's Last Branch Record Extension v2 (LbrExtV2) and the dependent LBR freeze feature to guests, so they can use the LBR v2 virtualization provided by KVM. The related KVM patches for this feature can be found at [1]. [1] https://lore.kernel.org/kvm/[email protected]/ This series is based on top of stable-11.0 (tag: v11.0.1) branch. Regards, Shivansh --- Shivansh Dhiman (2): target/i386: Add support for AMD LbrExtV2 target/i386: Add support for AMD LBR/PMC freeze target/i386/cpu.c | 26 +++++++++++++++++++++++--- target/i386/cpu.h | 4 +++- 2 files changed, 26 insertions(+), 4 deletions(-) base-commit: 6e9a825c1d4e7b62d072e99a89ecd1a74c7f0d55 -- 2.43.0
