Message-ID: <1e620e45-4ab6-ae2a-18f7-d0a5521c6c7f@gmail.com>
Date:   Sat, 11 Mar 2023 00:02:55 +0800
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Subject: Re: [RFC PATCH V3 16/16] x86/sev: Fix interrupt exit code paths from
 #HV exception
To:     "Gupta, Pankaj" <pankaj.gupta@amd.com>, luto@kernel.org,
        tglx@linutronix.de, mingo@redhat.com, bp@alien8.de,
        dave.hansen@linux.intel.com, x86@kernel.org, hpa@zytor.com,
        seanjc@google.com, pbonzini@redhat.com, jgross@suse.com,
        tiala@microsoft.com, kirill@shutemov.name,
        jiangshan.ljs@antgroup.com, peterz@infradead.org,
        ashish.kalra@amd.com, srutherford@google.com,
        akpm@linux-foundation.org, anshuman.khandual@arm.com,
        pawan.kumar.gupta@linux.intel.com, adrian.hunter@intel.com,
        daniel.sneddon@linux.intel.com, alexander.shishkin@linux.intel.com,
        sandipan.das@amd.com, ray.huang@amd.com, brijesh.singh@amd.com,
        michael.roth@amd.com, thomas.lendacky@amd.com,
        venu.busireddy@oracle.com, sterritt@google.com,
        tony.luck@intel.com, samitolvanen@google.com, fenghua.yu@intel.com
Cc:     linux-kernel@vger.kernel.org, kvm@vger.kernel.org,
        linux-hyperv@vger.kernel.org, linux-arch@vger.kernel.org
References: <20230122024607.788454-1-ltykernel@gmail.com>
 <20230122024607.788454-17-ltykernel@gmail.com>
 <65f08b1e-ecae-7100-cdbe-79e07ade90e4@amd.com>
From:   Tianyu Lan <ltykernel@gmail.com>
In-Reply-To: <65f08b1e-ecae-7100-cdbe-79e07ade90e4@amd.com>
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Precedence: bulk

On 2/22/2023 12:44 AM, Gupta, Pankaj wrote:
>> @@ -2529,3 +2537,25 @@ static int __init snp_init_platform_device(void)
>>       return 0;
>>   }
>>   device_initcall(snp_init_platform_device);
>> +
>> +noinstr void irqentry_exit_hv_cond(struct pt_regs *regs, 
>> irqentry_state_t state)
>> +{
> 
> This code path is being called even for the guest without SNP. Ran
> a SEV guest and guest crashed in this code path. Checking & returning
> made guest (non SNP) to boot with some call traces. But this branch 
> needs to be avoided for non-SNP guests and host as well.
> 

Nice catch! I will fix it in the next version.

Thanks.