Re: [PATCH v3 13/17] x86/xen: enable Hygon support to Xen

From: Boris Ostrovsky
Date: Sat Aug 11 2018 - 10:35:44 EST


On 08/11/2018 09:29 AM, Pu Wen wrote:
> To make Xen work correctly on Hygon platforms, reuse AMD's Xen support
> code path and add vendor check for Hygon along with AMD.
>
> Signed-off-by: Pu Wen <puwen@xxxxxxxx>
> ---
> arch/x86/xen/pmu.c | 15 ++++++++++++---
> 1 file changed, 12 insertions(+), 3 deletions(-)
>
> diff --git a/arch/x86/xen/pmu.c b/arch/x86/xen/pmu.c
> index 7d00d4a..1053dda 100644
> --- a/arch/x86/xen/pmu.c
> +++ b/arch/x86/xen/pmu.c
> @@ -90,6 +90,12 @@ static void xen_pmu_arch_init(void)
> k7_counters_mirrored = 0;
> break;
> }
> + } else if (boot_cpu_data.x86_vendor == X86_VENDOR_HYGON) {
> + amd_num_counters = F10H_NUM_COUNTERS;

I haven't looked in details at Zen's PMU but the PMC section in the spec
starts with
 "There are six core performance events counters per thread..."



> + amd_counters_base = MSR_K7_PERFCTR0;
> + amd_ctrls_base = MSR_K7_EVNTSEL0;
> + amd_msr_step = 1;
> + k7_counters_mirrored = 0;
> } else {
> uint32_t eax, ebx, ecx, edx;
>
> @@ -285,7 +291,8 @@ static bool xen_amd_pmu_emulate(unsigned int msr, u64 *val, bool is_read)
>
> bool pmu_msr_read(unsigned int msr, uint64_t *val, int *err)
> {
> - if (boot_cpu_data.x86_vendor == X86_VENDOR_AMD) {
> + if (boot_cpu_data.x86_vendor == X86_VENDOR_AMD ||
> + boot_cpu_data.x86_vendor == X86_VENDOR_HYGON) {


'if (boot_cpu_data.x86_vendor != X86_VENDOR_INTEL)' please.


-boris

> if (is_amd_pmu_msr(msr)) {
> if (!xen_amd_pmu_emulate(msr, val, 1))
> *val = native_read_msr_safe(msr, err);
> @@ -308,7 +315,8 @@ bool pmu_msr_write(unsigned int msr, uint32_t low, uint32_t high, int *err)
> {
> uint64_t val = ((uint64_t)high << 32) | low;
>
> - if (boot_cpu_data.x86_vendor == X86_VENDOR_AMD) {
> + if (boot_cpu_data.x86_vendor == X86_VENDOR_AMD ||
> + boot_cpu_data.x86_vendor == X86_VENDOR_HYGON) {
> if (is_amd_pmu_msr(msr)) {
> if (!xen_amd_pmu_emulate(msr, &val, 0))
> *err = native_write_msr_safe(msr, low, high);
> @@ -379,7 +387,8 @@ static unsigned long long xen_intel_read_pmc(int counter)
>
> unsigned long long xen_read_pmc(int counter)
> {
> - if (boot_cpu_data.x86_vendor == X86_VENDOR_AMD)
> + if (boot_cpu_data.x86_vendor == X86_VENDOR_AMD ||
> + boot_cpu_data.x86_vendor == X86_VENDOR_HYGON)
> return xen_amd_read_pmc(counter);
> else
> return xen_intel_read_pmc(counter);