Commit c63bbb7a40 for qemu.org
commit c63bbb7a400cc903b35a7a12e9a3628fc6173fd5
Author: Jon Kohler <jon@nutanix.com>
Date: Thu Nov 6 10:46:24 2025 -0700
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>
diff --git a/target/i386/cpu.c b/target/i386/cpu.c
index 987f64c5af..2a869f5b73 100644
--- a/target/i386/cpu.c
+++ b/target/i386/cpu.c
@@ -5809,6 +5809,15 @@ static const X86CPUDefinition builtin_x86_defs[] = {
{ /* end of list */ },
}
},
+ {
+ .version = 5,
+ .note = "with ITS_NO",
+ .cache_info = &xeon_srf_cache_info,
+ .props = (PropValue[]) {
+ { "its-no", "on" },
+ { /* end of list */ },
+ }
+ },
{ /* end of list */ },
},
},