Re: [libvirt PATCH 36/39] cpu_x86: Add support for stepping part of CPU signature

On a Friday in 2020, Jiri Denemark wrote: >CPU models defined in the cpu_map can use signature/@stepping attribute >to match a limited set of stepping numbers. The value is a bitmap for >bits 0..15 each corresponding to a single stepping value. For example, >stepping='4-6,9' will match 4, 5, 6, and 9. Omitting the attribute is >equivalent to stepping='0-15'. > >Signed-off-by: Jiri Denemark <jdenemar(a)redhat.com&gt; >--- > src/cpu/cpu_x86.c | 60 +++++++++++++++++++++++++++++++++++++++-------- > 1 file changed, 50 insertions(+), 10 deletions(-) > >diff --git a/src/cpu/cpu_x86.c b/src/cpu/cpu_x86.c >index 51c98efca9..bd224a9d0d 100644 >--- a/src/cpu/cpu_x86.c >+++ b/src/cpu/cpu_x86.c >@@ -125,6 +125,7 @@ typedef struct _virCPUx86Signature virCPUx86Signature; > struct _virCPUx86Signature { > unsigned int family; > unsigned int model; >+ virBitmapPtr stepping; > }; > > typedef struct _virCPUx86Signatures virCPUx86Signatures; >@@ -732,7 +733,17 @@ x86MakeSignature(unsigned int family, > static uint32_t > virCPUx86SignatureToCPUID(virCPUx86Signature *sig) > { >- return x86MakeSignature(sig->family, sig->model, 0); >+ unsigned int stepping = 0; >+ >+ if (sig->stepping) { >+ ssize_t fisrtBit; first? >+ >+ fisrtBit = virBitmapNextSetBit(sig->stepping, -1); >+ if (fisrtBit >= 0) >+ stepping = fisrtBit; >+ }

>+ >+ return x86MakeSignature(sig->family, sig->model, stepping); > } Reviewed-by: Ján Tomko <jtomko(a)redhat.com&gt;