2022-10-05 11:27:02

by Juergen Gross

Subject: [PATCH v3 2/4] xen/pv: fix vendor checks for pmu emulation

The CPU vendor checks for pmu emulation are rather limited today, as
the assumption seems to be that only Intel and AMD are existing and/or
supported vendors.

Fix that by handling Centaur and Zhaoxin CPUs the same way as Intel,
and Hygon the same way as AMD.

While at it fix the return type of is_intel_pmu_msr().

Suggested-by: Jan Beulich <[email protected]>
Signed-off-by: Juergen Gross <[email protected]>
---
V3:
- new patch
---
arch/x86/xen/pmu.c | 9 ++++++---
1 file changed, 6 insertions(+), 3 deletions(-)

diff --git a/arch/x86/xen/pmu.c b/arch/x86/xen/pmu.c
index 0f98cb1077e3..68aff1382872 100644
--- a/arch/x86/xen/pmu.c
+++ b/arch/x86/xen/pmu.c
@@ -131,7 +131,8 @@ static inline uint32_t get_fam15h_addr(u32 addr)

static inline bool is_amd_pmu_msr(unsigned int msr)
{
- if (boot_cpu_data.x86_vendor == X86_VENDOR_INTEL)
+ if (boot_cpu_data.x86_vendor != X86_VENDOR_AMD &&
+ boot_cpu_data.x86_vendor != X86_VENDOR_HYGON)
return false;

if ((msr >= MSR_F15H_PERF_CTL &&
@@ -143,11 +144,13 @@ static inline bool is_amd_pmu_msr(unsigned int msr)
return false;
}

-static int is_intel_pmu_msr(u32 msr_index, int *type, int *index)
+static bool is_intel_pmu_msr(u32 msr_index, int *type, int *index)
{
u32 msr_index_pmc;

- if (boot_cpu_data.x86_vendor != X86_VENDOR_INTEL)
+ if (boot_cpu_data.x86_vendor != X86_VENDOR_INTEL &&
+ boot_cpu_data.x86_vendor != X86_VENDOR_CENTAUR &&
+ boot_cpu_data.x86_vendor != X86_VENDOR_ZHAOXIN)
return false;

switch (msr_index) {
--
2.35.3

2022-10-05 12:28:25

by Jan Beulich

Subject: Re: [PATCH v3 2/4] xen/pv: fix vendor checks for pmu emulation

On 05.10.2022 13:03, Juergen Gross wrote:
> The CPU vendor checks for pmu emulation are rather limited today, as
> the assumption seems to be that only Intel and AMD are existing and/or
> supported vendors.
>
> Fix that by handling Centaur and Zhaoxin CPUs the same way as Intel,
> and Hygon the same way as AMD.
>
> While at it fix the return type of is_intel_pmu_msr().
>
> Suggested-by: Jan Beulich <[email protected]>
> Signed-off-by: Juergen Gross <[email protected]>

Reviewed-by: Jan Beulich <[email protected]>