From: Tianyu Lan <ltykernel@gmail.com>
To: "Michael Kelley (LINUX)" <mikelley@microsoft.com>,
KY Srinivasan <kys@microsoft.com>,
Haiyang Zhang <haiyangz@microsoft.com>,
"wei.liu@kernel.org" <wei.liu@kernel.org>,
Dexuan Cui <decui@microsoft.com>,
"tglx@linutronix.de" <tglx@linutronix.de>,
"mingo@redhat.com" <mingo@redhat.com>,
"bp@alien8.de" <bp@alien8.de>,
"dave.hansen@linux.intel.com" <dave.hansen@linux.intel.com>,
"x86@kernel.org" <x86@kernel.org>,
"hpa@zytor.com" <hpa@zytor.com>,
"daniel.lezcano@linaro.org" <daniel.lezcano@linaro.org>,
"arnd@arndb.de" <arnd@arndb.de>
Cc: Tianyu Lan <Tianyu.Lan@microsoft.com>,
"linux-arch@vger.kernel.org" <linux-arch@vger.kernel.org>,
"linux-hyperv@vger.kernel.org" <linux-hyperv@vger.kernel.org>,
"linux-kernel@vger.kernel.org" <linux-kernel@vger.kernel.org>,
"vkuznets@redhat.com" <vkuznets@redhat.com>
Subject: Re: [PATCH V3 5/9] x86/hyperv: Use vmmcall to implement Hyper-V hypercall in sev-snp enlightened guest
Date: Wed, 26 Jul 2023 21:47:03 +0800 [thread overview]
Message-ID: <89c9f27c-f539-ef75-dc67-bdb0a8480c4b@gmail.com> (raw)
In-Reply-To: <BYAPR21MB16882FAEDEFAED59208ED9E0D700A@BYAPR21MB1688.namprd21.prod.outlook.com>
On 7/26/2023 11:44 AM, Michael Kelley (LINUX) wrote:
>> diff --git a/arch/x86/include/asm/mshyperv.h b/arch/x86/include/asm/mshyperv.h
>> index 2fa38e9f6207..025eda129d99 100644
>> --- a/arch/x86/include/asm/mshyperv.h
>> +++ b/arch/x86/include/asm/mshyperv.h
>> @@ -64,12 +64,12 @@ static inline u64 hv_do_hypercall(u64 control, void *input, void *output)
>> if (!hv_hypercall_pg)
>> return U64_MAX;
>>
>> - __asm__ __volatile__("mov %4, %%r8\n"
>> - CALL_NOSPEC
>> + __asm__ __volatile__("mov %[output], %%r8\n"
>> + ALTERNATIVE("vmmcall", CALL_NOSPEC, X86_FEATURE_SEV_ES)
> Since this code is for SEV-SNP, what's the thinking behind using
> X86_FEATURE_SEV_ES in the ALTERNATIVE statements? Don't you need
> to use X86_FEATURE_SEV_SNP (which is being added in another patch set that
> Boris Petkov pointed out).
Hi Michael:
Thanks for your review. The patch mentioned by Boris has not been
merged and so still use X86_FEATURE_SEV_ES here. We may replace the
feature flag with X86_FEATURE_SEV_SNP after it's upstreamed.
>
> Also, does this patch depend on Peter Zijlstra's patch to support nested
> ALTERNATIVE statements? If so, that needs to be called out, probably in
> the cover letter. Peter's patch doesn't yet appear in linux-next.
>
It may work without Peterz's patch. Please see
https://lkml.org/lkml/2023/6/27/520.
Peterz's patch optimizes ALTERNATIVE_n implementation with nested
expression.
next prev parent reply other threads:[~2023-07-26 13:47 UTC|newest]
Thread overview: 18+ messages / expand[flat|nested] mbox.gz Atom feed top
2023-07-18 3:22 [PATCH V3 0/9] x86/hyperv: Add AMD sev-snp enlightened guest support on hyperv Tianyu Lan
2023-07-18 3:22 ` [PATCH V3 1/9] x86/hyperv: Add sev-snp enlightened guest static key Tianyu Lan
2023-07-26 3:26 ` Michael Kelley (LINUX)
2023-07-18 3:22 ` [PATCH V3 2/9] x86/hyperv: Set Virtual Trust Level in VMBus init message Tianyu Lan
2023-07-26 3:28 ` Michael Kelley (LINUX)
2023-07-18 3:22 ` [PATCH V3 3/9] x86/hyperv: Mark Hyper-V vp assist page unencrypted in SEV-SNP enlightened guest Tianyu Lan
2023-07-18 3:22 ` [PATCH V3 4/9] drivers: hv: Mark percpu hvcall input arg " Tianyu Lan
2023-07-18 3:22 ` [PATCH V3 5/9] x86/hyperv: Use vmmcall to implement Hyper-V hypercall in sev-snp " Tianyu Lan
2023-07-26 3:44 ` Michael Kelley (LINUX)
2023-07-26 13:47 ` Tianyu Lan [this message]
2023-07-26 14:29 ` Michael Kelley (LINUX)
2023-07-28 10:45 ` Tianyu Lan
2023-07-18 3:23 ` [PATCH V3 6/9] clocksource: hyper-v: Mark hyperv tsc page unencrypted " Tianyu Lan
2023-07-18 3:23 ` [PATCH V3 7/9] x86/hyperv: Initialize cpu and memory for SEV-SNP " Tianyu Lan
2023-07-26 4:26 ` Jinank Jain
2023-07-26 14:15 ` Tianyu Lan
2023-07-18 3:23 ` [PATCH V3 8/9] x86/hyperv: Add smp support for SEV-SNP guest Tianyu Lan
2023-07-18 3:23 ` [PATCH V3 9/9] x86/hyperv: Add hyperv-specific handling for VMMCALL under SEV-ES Tianyu Lan
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