From: Alexey Dobriyan <adobriyan@gmail.com>
To: kvm@vger.kernel.org
Cc: linux-kernel@vger.kernel.org, jpoimboe@kernel.org,
pbonzini@redhat.com, x86@kernel.org
Subject: VMX HOST_RIP target alignment
Date: Thu, 17 Nov 2022 23:46:09 +0300 [thread overview]
Message-ID: <Y3adkSe/J70PqUyt@p183> (raw)
One of the side effects of fixing retbleed for VMX was demoting
HOST_RIP target from honorable function to a lowly label:
-SYM_FUNC_START(vmx_vmexit)
+SYM_INNER_LABEL(vmx_vmexit, SYM_L_GLOBAL)
ffffffff81243c49: 0f 01 c2 vmlaunch
ffffffff81243c4c: e9 a7 00 00 00 jmp ffffffff81243cf8 <vmx_vmexit+0xa7>
ffffffff81243c51 <vmx_vmexit>:
ffffffff81243c51: 50 push rax
Now I've never measured VM exit latency but is it important to align it
at 16 bytes like Intel recommends for functions?
vmalexey
next reply other threads:[~2022-11-17 20:46 UTC|newest]
Thread overview: 2+ messages / expand[flat|nested] mbox.gz Atom feed top
2022-11-17 20:46 Alexey Dobriyan [this message]
2022-11-17 23:22 ` VMX HOST_RIP target alignment Josh Poimboeuf
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