From: Borislav Petkov <bp@alien8.de>
To: Brijesh Singh <brijesh.singh@amd.com>
Cc: linux-kernel@vger.kernel.org, x86@kernel.org,
kvm@vger.kernel.org, ak@linux.intel.com,
Thomas Gleixner <tglx@linutronix.de>,
Ingo Molnar <mingo@redhat.com>, Joerg Roedel <jroedel@suse.de>,
"H. Peter Anvin" <hpa@zytor.com>, Tony Luck <tony.luck@intel.com>,
Dave Hansen <dave.hansen@intel.com>,
"Peter Zijlstra (Intel)" <peterz@infradead.org>,
Paolo Bonzini <pbonzini@redhat.com>,
Tom Lendacky <thomas.lendacky@amd.com>,
David Rientjes <rientjes@google.com>,
Sean Christopherson <seanjc@google.com>
Subject: Re: [RFC Part1 PATCH 06/13] x86/compressed: rescinds and validate the memory used for the GHCB
Date: Wed, 7 Apr 2021 13:16:04 +0200 [thread overview]
Message-ID: <20210407111604.GA25319@zn.tnic> (raw)
In-Reply-To: <c9f60432-2484-be1e-7b08-86dae5aa263f@amd.com>
On Tue, Apr 06, 2021 at 10:47:18AM -0500, Brijesh Singh wrote:
> Before the GHCB is established the caller does not need to save and
> restore MSRs. The page_state_change() uses the GHCB MSR protocol and it
> can be called before and after the GHCB is established hence I am saving
> and restoring GHCB MSRs.
I think you need to elaborate on that, maybe with an example. What the
other sites using the GHCB MSR currently do is:
1. request by writing it
2. read the response
None of them save and restore it.
So why here?
Thx.
--
Regards/Gruss,
Boris.
https://people.kernel.org/tglx/notes-about-netiquette
next prev parent reply other threads:[~2021-04-07 11:16 UTC|newest]
Thread overview: 52+ messages / expand[flat|nested] mbox.gz Atom feed top
2021-03-24 16:44 [RFC Part1 PATCH 00/13] Add AMD Secure Nested Paging (SEV-SNP) Guest Support Brijesh Singh
2021-03-24 16:44 ` [RFC Part1 PATCH 01/13] x86/cpufeatures: Add SEV-SNP CPU feature Brijesh Singh
2021-03-25 10:54 ` Borislav Petkov
2021-03-25 14:50 ` Brijesh Singh
2021-03-25 16:29 ` Borislav Petkov
2021-03-24 16:44 ` [RFC Part1 PATCH 02/13] x86/mm: add sev_snp_active() helper Brijesh Singh
2021-03-24 16:44 ` [RFC Part1 PATCH 03/13] x86: add a helper routine for the PVALIDATE instruction Brijesh Singh
2021-03-26 14:30 ` Borislav Petkov
2021-03-26 15:42 ` Brijesh Singh
2021-03-26 18:22 ` Brijesh Singh
2021-03-26 19:12 ` Borislav Petkov
2021-03-26 20:04 ` Brijesh Singh
2021-03-26 19:22 ` Borislav Petkov
2021-03-26 20:01 ` Brijesh Singh
2021-03-24 16:44 ` [RFC Part1 PATCH 04/13] x86/sev-snp: define page state change VMGEXIT structure Brijesh Singh
2021-04-01 10:32 ` Borislav Petkov
2021-04-01 14:11 ` Brijesh Singh
2021-04-02 15:44 ` Borislav Petkov
2021-03-24 16:44 ` [RFC Part1 PATCH 05/13] X86/sev-es: move few helper functions in common file Brijesh Singh
2021-04-02 19:27 ` Borislav Petkov
2021-04-02 21:33 ` Brijesh Singh
2021-03-24 16:44 ` [RFC Part1 PATCH 06/13] x86/compressed: rescinds and validate the memory used for the GHCB Brijesh Singh
2021-04-06 10:33 ` Borislav Petkov
2021-04-06 15:47 ` Brijesh Singh
2021-04-06 19:42 ` Tom Lendacky
2021-04-07 11:25 ` Borislav Petkov
2021-04-07 19:45 ` Borislav Petkov
2021-04-08 13:57 ` Tom Lendacky
2021-04-07 11:16 ` Borislav Petkov [this message]
2021-04-07 13:35 ` Brijesh Singh
2021-04-07 14:21 ` Tom Lendacky
2021-04-07 17:15 ` Brijesh Singh
2021-03-24 16:44 ` [RFC Part1 PATCH 07/13] x86/compressed: register GHCB memory when SNP is active Brijesh Singh
2021-04-07 11:59 ` Borislav Petkov
2021-04-07 17:34 ` Brijesh Singh
2021-04-07 17:54 ` Tom Lendacky
2021-04-08 8:17 ` Borislav Petkov
2021-03-24 16:44 ` [RFC Part1 PATCH 08/13] x86/sev-es: register GHCB memory when SEV-SNP " Brijesh Singh
2021-04-08 8:38 ` Borislav Petkov
2021-03-24 16:44 ` [RFC Part1 PATCH 09/13] x86/kernel: add support to validate memory in early enc attribute change Brijesh Singh
2021-04-08 11:40 ` Borislav Petkov
2021-04-08 12:25 ` Brijesh Singh
2021-03-24 16:44 ` [RFC Part1 PATCH 10/13] X86: kernel: make the bss.decrypted section shared in RMP table Brijesh Singh
2021-03-24 16:44 ` [RFC Part1 PATCH 11/13] x86/kernel: validate rom memory before accessing when SEV-SNP is active Brijesh Singh
2021-04-09 16:53 ` Borislav Petkov
2021-04-09 17:40 ` Brijesh Singh
2021-03-24 16:44 ` [RFC Part1 PATCH 12/13] x86/sev-es: make GHCB get and put helper accessible outside Brijesh Singh
2021-03-24 16:44 ` [RFC Part1 PATCH 13/13] x86/kernel: add support to validate memory when changing C-bit Brijesh Singh
2021-04-12 11:49 ` Borislav Petkov
2021-04-12 12:55 ` Brijesh Singh
2021-04-12 13:05 ` Borislav Petkov
2021-04-12 14:31 ` Brijesh Singh
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