From: Nikunj A Dadhania <nikunj@amd.com>
To: Borislav Petkov <bp@alien8.de>, Sean Christopherson <seanjc@google.com>
Cc: Tom Lendacky <thomas.lendacky@amd.com>,
<linux-kernel@vger.kernel.org>, <x86@kernel.org>,
<tglx@linutronix.de>, <mingo@redhat.com>,
<dave.hansen@linux.intel.com>, <santosh.shukla@amd.com>
Subject: Re: [PATCH] x86/sev: Improve handling of writes to intercepted GUEST_TSC_FREQ
Date: Tue, 15 Jul 2025 09:13:10 +0000 [thread overview]
Message-ID: <85ecuhx1eh.fsf@amd.com> (raw)
In-Reply-To: <20250715083827.GBaHYTg9eU55LcHKR1@fat_crate.local>
Borislav Petkov <bp@alien8.de> writes:
> On Mon, Jul 14, 2025 at 09:36:04AM -0700, Sean Christopherson wrote:
>> Or as Tom suggested, return ES_EXCEPTION and let the kernel's normal machinery
>> WARN on the bad WRMSR.
>
> Ack.
That will panic the SNP guest instead of #GP:
root@ubuntu:~# wrmsr 0xc0010134 0
[ 20.804335] ------------[ cut here ]------------
[ 20.804336] WARNING: arch/x86/coco/sev/vc-handle.c:383 at vc_handle_exitcode.part.0+0xc1b/0x1090, CPU#0: wrmsr/607
...
[ 20.804507] SEV: Unsupported exception in #VC instruction emulation - can't continue
[ 20.804508] ------------[ cut here ]------------
[ 20.804508] kernel BUG at arch/x86/coco/sev/vc-handle.c:123!
[ 20.804514] Oops: invalid opcode: 0000 [#1] SMP NOPTI
Regards,
Nikunj
next prev parent reply other threads:[~2025-07-15 9:13 UTC|newest]
Thread overview: 15+ messages / expand[flat|nested] mbox.gz Atom feed top
2025-07-11 4:12 Nikunj A Dadhania
2025-07-14 10:44 ` Borislav Petkov
2025-07-14 14:24 ` Sean Christopherson
2025-07-14 14:59 ` Tom Lendacky
2025-07-14 15:17 ` Sean Christopherson
2025-07-14 16:16 ` Borislav Petkov
2025-07-14 16:36 ` Sean Christopherson
2025-07-15 8:37 ` Nikunj A Dadhania
2025-07-15 8:43 ` Borislav Petkov
2025-07-15 8:58 ` Nikunj A Dadhania
2025-07-15 8:38 ` Borislav Petkov
2025-07-15 9:13 ` Nikunj A Dadhania [this message]
2025-07-15 9:44 ` Borislav Petkov
2025-07-15 12:47 ` Tom Lendacky
2025-07-16 6:09 ` Nikunj A Dadhania
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