From: Ard Biesheuvel <ardb@kernel.org>
To: Kevin Loughlin <kevinloughlin@google.com>
Cc: Ard Biesheuvel <ardb+git@google.com>,
linux-kernel@vger.kernel.org,
Tom Lendacky <thomas.lendacky@amd.com>,
Dionna Glaze <dionnaglaze@google.com>,
Thomas Gleixner <tglx@linutronix.de>,
Ingo Molnar <mingo@redhat.com>, Borislav Petkov <bp@alien8.de>,
Dave Hansen <dave.hansen@linux.intel.com>,
Andy Lutomirski <luto@kernel.org>, Arnd Bergmann <arnd@arndb.de>,
Nathan Chancellor <nathan@kernel.org>,
Nick Desaulniers <ndesaulniers@google.com>,
Justin Stitt <justinstitt@google.com>,
Brian Gerst <brgerst@gmail.com>,
linux-arch@vger.kernel.org, llvm@lists.linux.dev
Subject: Re: [PATCH v2 16/17] x86/sev: Drop inline asm LEA instructions for RIP-relative references
Date: Fri, 26 Jan 2024 00:24:35 +0100 [thread overview]
Message-ID: <CAMj1kXE5bC-QgGWqhAtuRT5fDbBUgjkRyjGSwsiQcSgA-KuaYg@mail.gmail.com> (raw)
In-Reply-To: <CAGdbjmLEsj1cSnxoneSrDy2J2SFenjEdoYa_zoDQQhtU1nccMA@mail.gmail.com>
On Thu, 25 Jan 2024 at 21:46, Kevin Loughlin <kevinloughlin@google.com> wrote:
>
> On Thu, Jan 25, 2024 at 3:33 AM Ard Biesheuvel <ardb+git@google.com> wrote:
> >
> > The SEV code that may run early is now built with -fPIC and so there is
> > no longer a need for explicit RIP-relative references in inline asm,
> > given that is what the compiler will emit as well.
> >
> > Signed-off-by: Ard Biesheuvel <ardb@kernel.org>
> > ---
> > arch/x86/mm/mem_encrypt_identity.c | 37 +++-----------------
> > 1 file changed, 5 insertions(+), 32 deletions(-)
>
> snp_cpuid_get_table() in arch/x86/kernel/sev-shared.c (a helper
> function to provide the same inline assembly pattern for RIP-relative
> references) would also no longer be needed, as all calls to it would
> now be made in position-independent code. We can therefore eliminate
> the function as part of this commit.
Yes that would be another nice cleanup.
next prev parent reply other threads:[~2024-01-25 23:24 UTC|newest]
Thread overview: 21+ messages / expand[flat|nested] mbox.gz Atom feed top
2024-01-25 11:28 [PATCH v2 00/17] x86: Confine early 1:1 mapped startup code Ard Biesheuvel
2024-01-25 11:28 ` [PATCH v2 01/17] x86/startup_64: Drop long return to initial_code pointer Ard Biesheuvel
2024-01-25 11:28 ` [PATCH v2 02/17] x86/startup_64: Simplify calculation of initial page table address Ard Biesheuvel
2024-01-25 11:28 ` [PATCH v2 03/17] x86/startup_64: Simplify CR4 handling in startup code Ard Biesheuvel
2024-01-25 11:28 ` [PATCH v2 04/17] x86/startup_64: Drop global variables to keep track of LA57 state Ard Biesheuvel
2024-01-25 11:28 ` [PATCH v2 05/17] x86/startup_64: Simplify virtual switch on primary boot Ard Biesheuvel
2024-01-25 11:28 ` [PATCH v2 06/17] x86/head64: Replace pointer fixups with PIE codegen Ard Biesheuvel
2024-01-25 11:28 ` [PATCH v2 07/17] x86/head64: Simplify GDT/IDT initialization code Ard Biesheuvel
2024-01-25 11:28 ` [PATCH v2 08/17] asm-generic: Add special .pi.text section for position independent code Ard Biesheuvel
2024-01-25 11:28 ` [PATCH v2 09/17] x86: Move return_thunk to __pitext section Ard Biesheuvel
2024-01-25 11:28 ` [PATCH v2 10/17] x86/head64: Move early startup code into __pitext Ard Biesheuvel
2024-01-25 11:28 ` [PATCH v2 11/17] modpost: Warn about calls from __pitext into other text sections Ard Biesheuvel
2024-01-25 11:28 ` [PATCH v2 12/17] x86/coco: Make cc_set_mask() static inline Ard Biesheuvel
2024-01-25 11:28 ` [PATCH v2 13/17] x86/sev: Make all code reachable from 1:1 mapping __pitext Ard Biesheuvel
2024-01-25 11:28 ` [PATCH v2 14/17] x86/sev: Avoid WARN() in early code Ard Biesheuvel
2024-01-25 11:28 ` [PATCH v2 15/17] x86/sev: Use PIC codegen for early SEV startup code Ard Biesheuvel
2024-01-25 11:28 ` [PATCH v2 16/17] x86/sev: Drop inline asm LEA instructions for RIP-relative references Ard Biesheuvel
2024-01-25 20:46 ` Kevin Loughlin
2024-01-25 23:24 ` Ard Biesheuvel [this message]
2024-01-25 11:28 ` [PATCH v2 17/17] x86/startup_64: Don't bother setting up GS before the kernel is mapped Ard Biesheuvel
2024-01-25 22:23 ` [PATCH v2 00/17] x86: Confine early 1:1 mapped startup code Nathan Chancellor
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