@samitouri / QOSamiQemu / commits / c63bbb7a40

target/i386: introduce SierraForest-v5 to expose ITS_NO

Expose ITS_NO by default, as users using Sierra Forest and higher CPU models would not be able to live migrate to lower CPU hosts due to missing features. In that case, they would not be vulnerable to ITS. its-no was originally added on [1], but needs to be exposed on the individual CPU models for the guests to see by default. Note: For SRF, version 2 already exposed BHI_CTRL, which would already mark the CPU as invulnerable to ITS (at least in Linux); however, expose ITS_NO for completeness. [1] 74978391b2da ("target/i386: Make ITS_NO available to guests") Cc: Pawan Gupta <pawan.kumar.gupta@linux.intel.com> Signed-off-by: Jon Kohler <jon@nutanix.com> Link: https://lore.kernel.org/r/20251106174626.49930-5-jon@nutanix.com Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>

Jon Kohler committed Nov 6, 2025 at 10:46 UTC c63bbb7a400cc903b35a7a12e9a3628fc6173fd5
1 file changed +9
target/i386/cpu.c
+9
@@ -5809,6 +5809,15 @@ static const X86CPUDefinition builtin_x86_defs[] = {
5809 { /* end of list */ },
5810 }
5811 },
5812 + {
5813 + .version = 5,
5814 + .note = "with ITS_NO",
5815 + .cache_info = &xeon_srf_cache_info,
5816 + .props = (PropValue[]) {
5817 + { "its-no", "on" },
5818 + { /* end of list */ },
5819 + }
5820 + },
5821 { /* end of list */ },
5822 },
5823 },