linux-coco.lists.linux.dev archive mirror
 help / color / mirror / Atom feed
From: Sean Christopherson <seanjc@google.com>
To: Joerg Roedel <joro@8bytes.org>
Cc: x86@kernel.org, Eric Biederman <ebiederm@xmission.com>,
	kexec@lists.infradead.org, Joerg Roedel <jroedel@suse.de>,
	hpa@zytor.com, Andy Lutomirski <luto@kernel.org>,
	Dave Hansen <dave.hansen@linux.intel.com>,
	Peter Zijlstra <peterz@infradead.org>,
	Jiri Slaby <jslaby@suse.cz>,
	Dan Williams <dan.j.williams@intel.com>,
	Tom Lendacky <thomas.lendacky@amd.com>,
	Juergen Gross <jgross@suse.com>,
	Kees Cook <keescook@chromium.org>,
	David Rientjes <rientjes@google.com>,
	Cfir Cohen <cfir@google.com>, Erdem Aktas <erdemaktas@google.com>,
	Masami Hiramatsu <mhiramat@kernel.org>,
	Mike Stunes <mstunes@vmware.com>,
	Martin Radev <martin.b.radev@gmail.com>,
	Arvind Sankar <nivedita@alum.mit.edu>,
	linux-coco@lists.linux.dev, linux-kernel@vger.kernel.org,
	kvm@vger.kernel.org, virtualization@lists.linux-foundation.org
Subject: Re: [PATCH 11/12] x86/sev: Handle CLFLUSH MMIO events
Date: Fri, 30 Jul 2021 22:42:30 +0000	[thread overview]
Message-ID: <YQSAVo0CXUKHXdLF@google.com> (raw)
In-Reply-To: <20210721142015.1401-12-joro@8bytes.org>

On Wed, Jul 21, 2021, Joerg Roedel wrote:
> From: Joerg Roedel <jroedel@suse.de>
> 
> Handle CLFLUSH instruction to MMIO memory in the #VC handler. The
                               ^
			       |- emulated

> instruction is ignored by the handler, as the Hypervisor is
> responsible for cache management of emulated MMIO memory.
> 
> Signed-off-by: Joerg Roedel <jroedel@suse.de>
> ---
>  arch/x86/kernel/sev-shared.c | 9 +++++++++
>  1 file changed, 9 insertions(+)
> 
> diff --git a/arch/x86/kernel/sev-shared.c b/arch/x86/kernel/sev-shared.c
> index a7a0793c4f98..682fa202444f 100644
> --- a/arch/x86/kernel/sev-shared.c
> +++ b/arch/x86/kernel/sev-shared.c
> @@ -632,6 +632,15 @@ static enum es_result vc_handle_mmio_twobyte_ops(struct ghcb *ghcb,
>  	long *reg_data;
>  
>  	switch (insn->opcode.bytes[1]) {
> +		/* CLFLUSH */
> +	case 0xae:
> +		/*
> +		 * Ignore CLFLUSHes - those go to emulated MMIO anyway and the
> +		 * hypervisor is responsible for cache management.

This wording can be misread as "the hypervisor is responsible for _all_ cache
management".  Maybe just:

		/*
		 * Ignore CLFLUSHes - the hyperivsor is responsible for cache
		 * management of emulated MMIO.
		 */

Side topic, out of curisoity, what's mapping/accessing emulated MMIO as non-UC?

> +		 */
> +		ret = ES_OK;
> +		break;
> +
>  		/* MMIO Read w/ zero-extension */
>  	case 0xb6:
>  		bytes = 1;
> -- 
> 2.31.1
> 

  reply	other threads:[~2021-07-30 22:42 UTC|newest]

Thread overview: 18+ messages / expand[flat|nested]  mbox.gz  Atom feed  top
2021-07-21 14:20 [PATCH 00/12] x86/sev: KEXEC/KDUMP support for SEV-ES guests Joerg Roedel
2021-07-21 14:20 ` [PATCH 01/12] kexec: Allow architecture code to opt-out at runtime Joerg Roedel
2022-04-21 13:20   ` Tao Liu
2021-07-21 14:20 ` [PATCH 02/12] x86/kexec/64: Forbid kexec when running as an SEV-ES guest Joerg Roedel
2021-07-21 14:20 ` [PATCH 03/12] x86/sev: Save and print negotiated GHCB protocol version Joerg Roedel
2021-07-21 14:20 ` [PATCH 04/12] x86/sev: Do not hardcode " Joerg Roedel
2021-07-21 21:17   ` Tom Lendacky
2021-07-31  7:18     ` Joerg Roedel
2021-07-21 14:20 ` [PATCH 05/12] x86/sev: Use GHCB protocol version 2 if supported Joerg Roedel
2021-07-21 14:20 ` [PATCH 06/12] x86/sev: Cache AP Jump Table Address Joerg Roedel
2021-07-21 14:20 ` [PATCH 07/12] x86/sev: Setup code to park APs in the AP Jump Table Joerg Roedel
2021-07-21 14:20 ` [PATCH 08/12] x86/sev: Park APs on AP Jump Table with GHCB protocol version 2 Joerg Roedel
2021-07-21 14:20 ` [PATCH 09/12] x86/sev: Use AP Jump Table blob to stop CPU Joerg Roedel
2021-07-21 14:20 ` [PATCH 10/12] x86/sev: Add MMIO handling support to boot/compressed/ code Joerg Roedel
2021-07-21 14:20 ` [PATCH 11/12] x86/sev: Handle CLFLUSH MMIO events Joerg Roedel
2021-07-30 22:42   ` Sean Christopherson [this message]
2021-07-31  7:17     ` Joerg Roedel
2021-07-21 14:20 ` [PATCH 12/12] x86/sev: Support kexec under SEV-ES with AP Jump Table blob Joerg Roedel

Reply instructions:

You may reply publicly to this message via plain-text email
using any one of the following methods:

* Save the following mbox file, import it into your mail client,
  and reply-to-all from there: mbox

  Avoid top-posting and favor interleaved quoting:
  https://en.wikipedia.org/wiki/Posting_style#Interleaved_style

* Reply using the --to, --cc, and --in-reply-to
  switches of git-send-email(1):

  git send-email \
    --in-reply-to=YQSAVo0CXUKHXdLF@google.com \
    --to=seanjc@google.com \
    --cc=cfir@google.com \
    --cc=dan.j.williams@intel.com \
    --cc=dave.hansen@linux.intel.com \
    --cc=ebiederm@xmission.com \
    --cc=erdemaktas@google.com \
    --cc=hpa@zytor.com \
    --cc=jgross@suse.com \
    --cc=joro@8bytes.org \
    --cc=jroedel@suse.de \
    --cc=jslaby@suse.cz \
    --cc=keescook@chromium.org \
    --cc=kexec@lists.infradead.org \
    --cc=kvm@vger.kernel.org \
    --cc=linux-coco@lists.linux.dev \
    --cc=linux-kernel@vger.kernel.org \
    --cc=luto@kernel.org \
    --cc=martin.b.radev@gmail.com \
    --cc=mhiramat@kernel.org \
    --cc=mstunes@vmware.com \
    --cc=nivedita@alum.mit.edu \
    --cc=peterz@infradead.org \
    --cc=rientjes@google.com \
    --cc=thomas.lendacky@amd.com \
    --cc=virtualization@lists.linux-foundation.org \
    --cc=x86@kernel.org \
    /path/to/YOUR_REPLY

  https://kernel.org/pub/software/scm/git/docs/git-send-email.html

* If your mail client supports setting the In-Reply-To header
  via mailto: links, try the mailto: link
Be sure your reply has a Subject: header at the top and a blank line before the message body.
This is a public inbox, see mirroring instructions
for how to clone and mirror all data and code used for this inbox;
as well as URLs for NNTP newsgroup(s).