From: Sean Christopherson <sean.j.christopherson@intel.com>
To: Joerg Roedel <joro@8bytes.org>
Cc: x86@kernel.org, Joerg Roedel <jroedel@suse.de>,
Thomas Gleixner <tglx@linutronix.de>,
Ingo Molnar <mingo@redhat.com>, Borislav Petkov <bp@alien8.de>,
"H. Peter Anvin" <hpa@zytor.com>,
Dave Hansen <dave.hansen@linux.intel.com>,
Andy Lutomirski <luto@kernel.org>,
Peter Zijlstra <peterz@infradead.org>,
Kees Cook <keescook@chromium.org>,
Arvind Sankar <nivedita@alum.mit.edu>,
Martin Radev <martin.b.radev@gmail.com>,
Tom Lendacky <thomas.lendacky@amd.com>,
linux-kernel@vger.kernel.org
Subject: Re: [PATCH 1/5] x86/boot/compressed/64: Introduce sev_status
Date: Mon, 19 Oct 2020 17:59:25 -0700 [thread overview]
Message-ID: <20201020005925.GA24596@linux.intel.com> (raw)
In-Reply-To: <20201019151121.826-2-joro@8bytes.org>
On Mon, Oct 19, 2020 at 05:11:17PM +0200, Joerg Roedel wrote:
> From: Joerg Roedel <jroedel@suse.de>
>
> Introduce sev_status and initialize it together with sme_me_mask to have
> an indicator which SEV features are enabled.
>
> Signed-off-by: Joerg Roedel <jroedel@suse.de>
> ---
> arch/x86/boot/compressed/mem_encrypt.S | 14 +++++++++++++-
> 1 file changed, 13 insertions(+), 1 deletion(-)
>
> diff --git a/arch/x86/boot/compressed/mem_encrypt.S b/arch/x86/boot/compressed/mem_encrypt.S
> index dd07e7b41b11..0effd58f0095 100644
> --- a/arch/x86/boot/compressed/mem_encrypt.S
> +++ b/arch/x86/boot/compressed/mem_encrypt.S
> @@ -71,6 +71,8 @@ SYM_FUNC_END(get_sev_encryption_bit)
> SYM_FUNC_START(set_sev_encryption_mask)
> #ifdef CONFIG_AMD_MEM_ENCRYPT
> push %rbp
> + push %rax
> + push %rcx
There's no need to save/restore RAX and RCX, they are callee save. This
function is only called from C, so I doubt it's using a custom ABI.
> push %rdx
>
> movq %rsp, %rbp /* Save current stack pointer */
> @@ -81,10 +83,19 @@ SYM_FUNC_START(set_sev_encryption_mask)
>
> bts %rax, sme_me_mask(%rip) /* Create the encryption mask */
>
> + /* Read sev_status */
> + movl $MSR_AMD64_SEV, %ecx
> + rdmsr
> + shlq $32, %rdx
> + orq %rdx, %rax
> + movq %rax, sev_status(%rip)
> +
> .Lno_sev_mask:
> movq %rbp, %rsp /* Restore original stack pointer */
>
> pop %rdx
> + pop %rcx
> + pop %rax
> pop %rbp
> #endif
>
> @@ -96,5 +107,6 @@ SYM_FUNC_END(set_sev_encryption_mask)
>
> #ifdef CONFIG_AMD_MEM_ENCRYPT
> .balign 8
> -SYM_DATA(sme_me_mask, .quad 0)
> +SYM_DATA(sme_me_mask, .quad 0)
> +SYM_DATA(sev_status, .quad 0)
> #endif
> --
> 2.28.0
>
next prev parent reply other threads:[~2020-10-20 0:59 UTC|newest]
Thread overview: 19+ messages / expand[flat|nested] mbox.gz Atom feed top
2020-10-19 15:11 [PATCH 0/5] x86/sev-es: Mitigate some HV attack vectors Joerg Roedel
2020-10-19 15:11 ` [PATCH 1/5] x86/boot/compressed/64: Introduce sev_status Joerg Roedel
2020-10-20 0:59 ` Sean Christopherson [this message]
2020-10-20 1:08 ` Sean Christopherson
2020-10-20 9:55 ` Joerg Roedel
2020-10-19 15:11 ` [PATCH 2/5] x86/boot/compressed/64: Add CPUID sanity check to early #VC handler Joerg Roedel
2020-10-19 15:11 ` [PATCH 3/5] x86/boot/compressed/64: Check SEV encryption in 64-bit boot-path Joerg Roedel
2020-10-19 17:00 ` Arvind Sankar
2020-10-19 17:54 ` Arvind Sankar
2020-10-19 20:39 ` Joerg Roedel
2020-10-19 21:31 ` Arvind Sankar
2020-10-20 8:59 ` Joerg Roedel
2020-10-20 14:33 ` Arvind Sankar
2020-10-20 15:44 ` Joerg Roedel
2020-10-19 20:33 ` Joerg Roedel
2020-10-19 21:22 ` Arvind Sankar
2020-10-20 9:41 ` Joerg Roedel
2020-10-19 15:11 ` [PATCH 4/5] x86/head/64: Check SEV encryption before switching to kernel page-table Joerg Roedel
2020-10-19 15:11 ` [PATCH 5/5] x86/sev-es: Do not support MMIO to/from encrypted memory 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=20201020005925.GA24596@linux.intel.com \
--to=sean.j.christopherson@intel.com \
--cc=bp@alien8.de \
--cc=dave.hansen@linux.intel.com \
--cc=hpa@zytor.com \
--cc=joro@8bytes.org \
--cc=jroedel@suse.de \
--cc=keescook@chromium.org \
--cc=linux-kernel@vger.kernel.org \
--cc=luto@kernel.org \
--cc=martin.b.radev@gmail.com \
--cc=mingo@redhat.com \
--cc=nivedita@alum.mit.edu \
--cc=peterz@infradead.org \
--cc=tglx@linutronix.de \
--cc=thomas.lendacky@amd.com \
--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).