Re: [libvirt PATCH 33/39] cpu_x86: Introduce virCPUx86SignatureFromCPUID

[Ján Tomko]

On a Friday in 2020, Jiri Denemark wrote:

It can be used for separating family, model, and stepping numbers from a
single 32b integer as reported by CPUID.

Signed-off-by: Jiri Denemark 
---
src/cpu/cpu_x86.c | 19 ++-
1 file changed, 14 insertions(+), 5 deletions(-)



Reviewed-by: Ján Tomko 

Jano


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[libvirt PATCH 33/39] cpu_x86: Introduce virCPUx86SignatureFromCPUID

[Jiri Denemark]

It can be used for separating family, model, and stepping numbers from a
single 32b integer as reported by CPUID.

Signed-off-by: Jiri Denemark 
---
 src/cpu/cpu_x86.c | 19 ++-
 1 file changed, 14 insertions(+), 5 deletions(-)

diff --git a/src/cpu/cpu_x86.c b/src/cpu/cpu_x86.c
index a71b5ccacc..29c6e2b6be 100644
--- a/src/cpu/cpu_x86.c
+++ b/src/cpu/cpu_x86.c
@@ -717,6 +717,18 @@ x86MakeSignature(unsigned int family,
 }
 
 
+static void
+virCPUx86SignatureFromCPUID(uint32_t sig,
+unsigned int *family,
+unsigned int *model,
+unsigned int *stepping)
+{
+*family = ((sig >> 20) & 0xff) + ((sig >> 8) & 0xf);
+*model = ((sig >> 12) & 0xf0) + ((sig >> 4) & 0xf);
+*stepping = sig & 0xf;
+}
+
+
 static void
 x86DataToSignatureFull(const virCPUx86Data *data,
unsigned int *family,
@@ -725,17 +737,14 @@ x86DataToSignatureFull(const virCPUx86Data *data,
 {
 virCPUx86DataItem leaf1 = CPUID(.eax_in = 0x1);
 virCPUx86DataItemPtr item;
-virCPUx86CPUIDPtr cpuid;
 
 *family = *model = *stepping = 0;
 
 if (!(item = virCPUx86DataGet(data, )))
 return;
 
-cpuid = >data.cpuid;
-*family = ((cpuid->eax >> 20) & 0xff) + ((cpuid->eax >> 8) & 0xf);
-*model = ((cpuid->eax >> 12) & 0xf0) + ((cpuid->eax >> 4) & 0xf);
-*stepping = cpuid->eax & 0xf;
+virCPUx86SignatureFromCPUID(item->data.cpuid.eax,
+family, model, stepping);
 }
 
 
-- 
2.26.0