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

From: Boris Ostrovsky <boris.ostrovsky@oracle.com>
To: Pu Wen <puwen@hygon.cn>,
	tglx@linutronix.de, mingo@redhat.com, hpa@zytor.com,
	x86@kernel.org, thomas.lendacky@amd.com, bp@alien8.de,
	pbonzini@redhat.com, jgross@suse.com, JBeulich@suse.com
Cc: linux-kernel@vger.kernel.org, linux-arch@vger.kernel.org,
	xen-devel@lists.xenproject.org
Subject: Re: [PATCH v3 13/17] x86/xen: enable Hygon support to Xen
Date: Sat, 11 Aug 2018 10:34:18 -0400	[thread overview]
Message-ID: <b32887e0-df6e-fb31-d9cd-6b31961c9c2b@oracle.com> (raw)
In-Reply-To: <2747ad959f07459000f2693a98d237e2b3149ca1.1533989493.git.puwen@hygon.cn>

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@hygon.cn>
> ---
>  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);