This is prep work, split out to simply the diff on the following change.
* Split the INTEL check out of the IvyBridge RDRAND check, as the former will
be reused.
* Use asm/intel-family.h to remove a raw 0x3a model number.
No functional change.
Signed-off-by: Andrew Cooper <andrew.coop...@citrix.com>
---
CC: Jan Beulich <jbeul...@suse.com>
CC: Roger Pau Monné <roger....@citrix.com>
CC: Wei Liu <w...@xen.org>
---
xen/arch/x86/cpu-policy.c | 34 +++++++++++++++++++---------------
1 file changed, 19 insertions(+), 15 deletions(-)
diff --git a/xen/arch/x86/cpu-policy.c b/xen/arch/x86/cpu-policy.c
index 74266d30b551..bdbc5660acd4 100644
--- a/xen/arch/x86/cpu-policy.c
+++ b/xen/arch/x86/cpu-policy.c
@@ -10,6 +10,7 @@
#include <asm/cpu-policy.h>
#include <asm/hvm/nestedhvm.h>
#include <asm/hvm/svm/svm.h>
+#include <asm/intel-family.h>
#include <asm/msr-index.h>
#include <asm/paging.h>
#include <asm/setup.h>
@@ -429,21 +430,24 @@ static void __init
guest_common_max_feature_adjustments(uint32_t *fs)
static void __init guest_common_default_feature_adjustments(uint32_t *fs)
{
- /*
- * IvyBridge client parts suffer from leakage of RDRAND data due to SRBDS
- * (XSA-320 / CVE-2020-0543), and won't be receiving microcode to
- * compensate.
- *
- * Mitigate by hiding RDRAND from guests by default, unless explicitly
- * overridden on the Xen command line (cpuid=rdrand). Irrespective of the
- * default setting, guests can use RDRAND if explicitly enabled
- * (cpuid="host,rdrand=1") in the VM's config file, and VMs which were
- * previously using RDRAND can migrate in.
- */
- if ( boot_cpu_data.x86_vendor == X86_VENDOR_INTEL &&
- boot_cpu_data.x86 == 6 && boot_cpu_data.x86_model == 0x3a &&
- cpu_has_rdrand && !is_forced_cpu_cap(X86_FEATURE_RDRAND) )
- __clear_bit(X86_FEATURE_RDRAND, fs);
+ if ( boot_cpu_data.x86_vendor == X86_VENDOR_INTEL )
+ {
+ /*
+ * IvyBridge client parts suffer from leakage of RDRAND data due to
SRBDS
+ * (XSA-320 / CVE-2020-0543), and won't be receiving microcode to
+ * compensate.
+ *
+ * Mitigate by hiding RDRAND from guests by default, unless explicitly
+ * overridden on the Xen command line (cpuid=rdrand). Irrespective of
the
+ * default setting, guests can use RDRAND if explicitly enabled
+ * (cpuid="host,rdrand=1") in the VM's config file, and VMs which were
+ * previously using RDRAND can migrate in.
+ */
+ if ( boot_cpu_data.x86 == 6 &&
+ boot_cpu_data.x86_model == INTEL_FAM6_IVYBRIDGE &&
+ cpu_has_rdrand && !is_forced_cpu_cap(X86_FEATURE_RDRAND) )
+ __clear_bit(X86_FEATURE_RDRAND, fs);
+ }
/*
* On certain hardware, speculative or errata workarounds can result in
--
2.30.2
