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[Qemu-devel] [PATCH QEMU] Patches for new AMD CPU bits.

From: Konrad Rzeszutek Wilk
Subject: [Qemu-devel] [PATCH QEMU] Patches for new AMD CPU bits.
Date: Fri, 1 Jun 2018 11:38:07 -0400


I was reading the AMD whitepaper on SSBD and noticed that they have added
two new bits in the 8000_0008 CPUID. EBX:
 1) Bit[26] - similar to Intel's SSB_NO not needed anymore.
 2) Bit[24] - use SPEC_CTRL MSR (0x48) instead of VIRT SPEC_CTRL MSR

See 124441_AMD64_SpeculativeStoreBypassDisable_Whitepaper_final.pdf
A copy of this document is available at

These two patches along with the kernel ones allow us to expose those
two bits to the guest.

Thank you!

 target/i386/cpu.c | 2 +-
 1 file changed, 1 insertion(+), 1 deletion(-)

Konrad Rzeszutek Wilk (2):
      i386: define the AMD 'amd-ssbd' CPUID feature bit
      i386: Define AMD's no SSB mitigation needed.

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