From: Peter Zijlstra <peterz@infradead.org>
To: Paolo Bonzini <pbonzini@redhat.com>
Cc: x86@kernel.org, kys@microsoft.com, haiyangz@microsoft.com,
wei.liu@kernel.org, decui@microsoft.com, tglx@linutronix.de,
mingo@redhat.com, bp@alien8.de, dave.hansen@linux.intel.com,
hpa@zytor.com, seanjc@google.com, ardb@kernel.org,
kees@kernel.org, Arnd Bergmann <arnd@arndb.de>,
gregkh@linuxfoundation.org, jpoimboe@kernel.org,
linux-hyperv@vger.kernel.org, linux-kernel@vger.kernel.org,
kvm@vger.kernel.org, linux-efi@vger.kernel.org,
samitolvanen@google.com, ojeda@kernel.org
Subject: Re: [PATCH v2 00/13] objtool: Detect and warn about indirect calls in __nocfi functions
Date: Fri, 2 May 2025 13:08:17 +0200 [thread overview]
Message-ID: <20250502110817.GX4198@noisy.programming.kicks-ass.net> (raw)
In-Reply-To: <CABgObfZQ2n6PB0i4Uc6k4Rm9bVESt0aafOcdLzW4hwX3sN-ExA@mail.gmail.com>
On Thu, May 01, 2025 at 08:33:57PM +0200, Paolo Bonzini wrote:
> On Wed, Apr 30, 2025 at 1:26 PM Peter Zijlstra <peterz@infradead.org> wrote:
> > Notably the KVM fastop emulation stuff -- which I've completely rewritten for
> > this version -- the generated code doesn't look horrific, but is slightly more
> > verbose. I'm running on the assumption that instruction emulation is not super
> > performance critical these days of zero VM-exit VMs etc.
>
> It's definitely going to be slower, but I guess it's okay these days.
Yeah, it adds a bunch of branches at the very least. But that was indeed
the argument, we shouldn't care much these days.
> It's really only somewhat hot with really old processors
> (pre-Westmere) and only when running big real mode code.
Right, really old stuff :-)
prev parent reply other threads:[~2025-05-02 11:08 UTC|newest]
Thread overview: 52+ messages / expand[flat|nested] mbox.gz Atom feed top
2025-04-30 11:07 [PATCH v2 00/13] objtool: Detect and warn about indirect calls in __nocfi functions Peter Zijlstra
2025-04-30 11:07 ` [PATCH v2 01/13] x86/kvm/emulate: Implement test_cc() in C Peter Zijlstra
2025-04-30 11:07 ` [PATCH v2 02/13] x86/kvm/emulate: Introduce COP1 Peter Zijlstra
2025-04-30 16:19 ` Josh Poimboeuf
2025-04-30 19:05 ` Peter Zijlstra
2025-04-30 11:07 ` [PATCH v2 03/13] x86/kvm/emulate: Introduce COP2 Peter Zijlstra
2025-04-30 11:07 ` [PATCH v2 04/13] x86/kvm/emulate: Introduce COP2R Peter Zijlstra
2025-04-30 11:07 ` [PATCH v2 05/13] x86/kvm/emulate: Introduce COP2W Peter Zijlstra
2025-04-30 11:07 ` [PATCH v2 06/13] x86/kvm/emulate: Introduce COP2CL Peter Zijlstra
2025-04-30 11:07 ` [PATCH v2 07/13] x86/kvm/emulate: Introduce COP1SRC2 Peter Zijlstra
2025-04-30 11:07 ` [PATCH v2 08/13] x86/kvm/emulate: Introduce COP3WCL Peter Zijlstra
2025-04-30 11:07 ` [PATCH v2 09/13] x86/kvm/emulate: Convert em_salc() to C Peter Zijlstra
2025-04-30 11:07 ` [PATCH v2 10/13] x86/kvm/emulate: Remove fastops Peter Zijlstra
2025-04-30 11:07 ` [PATCH v2 11/13] x86,hyperv: Clean up hv_do_hypercall() Peter Zijlstra
2025-05-01 2:36 ` Michael Kelley
2025-04-30 11:07 ` [PATCH v2 12/13] x86_64,hyperv: Use direct call to hypercall-page Peter Zijlstra
2025-05-01 2:36 ` Michael Kelley
2025-05-01 8:59 ` Peter Zijlstra
2025-04-30 11:07 ` [PATCH v2 13/13] objtool: Validate kCFI calls Peter Zijlstra
2025-04-30 15:59 ` Josh Poimboeuf
2025-04-30 19:03 ` Peter Zijlstra
2025-05-01 15:56 ` Peter Zijlstra
2025-04-30 14:24 ` [PATCH v2 00/13] objtool: Detect and warn about indirect calls in __nocfi functions H. Peter Anvin
2025-04-30 19:06 ` Peter Zijlstra
2025-05-01 10:30 ` Peter Zijlstra
2025-05-01 15:38 ` Peter Zijlstra
2025-05-01 18:30 ` Sean Christopherson
2025-05-01 18:42 ` H. Peter Anvin
2025-05-01 18:59 ` Sean Christopherson
2025-05-02 6:12 ` Xin Li
2025-05-02 5:46 ` Xin Li
2025-05-02 5:48 ` Xin Li
2025-05-02 19:43 ` H. Peter Anvin
2025-05-02 8:40 ` Peter Zijlstra
2025-05-02 19:53 ` Sean Christopherson
2025-05-03 9:50 ` Peter Zijlstra
2025-05-03 18:28 ` Josh Poimboeuf
2025-05-06 7:31 ` Peter Zijlstra
2025-05-06 13:32 ` Peter Zijlstra
2025-05-06 19:18 ` Josh Poimboeuf
2025-05-28 7:44 ` Peter Zijlstra
2025-05-28 16:30 ` Peter Zijlstra
2025-05-28 16:35 ` Peter Zijlstra
2025-05-29 9:30 ` Peter Zijlstra
2025-06-03 5:43 ` Josh Poimboeuf
2025-06-03 16:29 ` Josh Poimboeuf
2025-06-05 17:19 ` Josh Poimboeuf
2025-06-06 10:49 ` Peter Zijlstra
2025-06-06 13:15 ` Sean Christopherson
2025-06-06 13:20 ` Peter Zijlstra
2025-05-01 18:33 ` Paolo Bonzini
2025-05-02 11:08 ` Peter Zijlstra [this message]
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