From: Jan Beulich <jbeulich@suse.com>
To: Andrew Cooper <andrew.cooper3@citrix.com>
Cc: "Roger Pau Monné" <roger.pau@citrix.com>, "Wei Liu" <wl@xen.org>,
"Jun Nakajima" <jun.nakajima@intel.com>,
"Kevin Tian" <kevin.tian@intel.com>,
Xen-devel <xen-devel@lists.xenproject.org>
Subject: Re: [PATCH 2/3] x86/spec-ctrl: Drop SPEC_CTRL_{ENTRY_FROM,EXIT_TO}_HVM
Date: Mon, 17 Jan 2022 12:22:41 +0100 [thread overview]
Message-ID: <aebd4542-8eb8-5073-a578-5b96a6354b84@suse.com> (raw)
In-Reply-To: <20220113163833.3831-3-andrew.cooper3@citrix.com>
On 13.01.2022 17:38, Andrew Cooper wrote:
> --- a/xen/arch/x86/hvm/svm/entry.S
> +++ b/xen/arch/x86/hvm/svm/entry.S
> @@ -59,7 +59,7 @@ __UNLIKELY_END(nsvm_hap)
> mov VCPUMSR_spec_ctrl_raw(%rax), %eax
>
> /* WARNING! `ret`, `call *`, `jmp *` not safe beyond this point. */
> - SPEC_CTRL_EXIT_TO_HVM /* Req: a=spec_ctrl %rsp=regs/cpuinfo, Clob: cd */
> + /* SPEC_CTRL_EXIT_TO_SVM (nothing currently) */
>
> pop %r15
> pop %r14
> @@ -86,7 +86,8 @@ __UNLIKELY_END(nsvm_hap)
>
> GET_CURRENT(bx)
>
> - SPEC_CTRL_ENTRY_FROM_HVM /* Req: b=curr %rsp=regs/cpuinfo, Clob: acd */
> + /* SPEC_CTRL_ENTRY_FROM_SVM Req: b=curr %rsp=regs/cpuinfo, Clob: ac */
> + ALTERNATIVE "", DO_OVERWRITE_RSB, X86_FEATURE_SC_RSB_HVM
Just for my own understanding: The comments you add aren't commented
out macro invocations (as I did read it first), but comments naming
would-be-macros which are then expanded "manually"? That is partly
because initially I read the description saying "Expand and drop the
macros" as meaning that the macros grow in what they contain, which
looked contradictory to them getting dropped at the same time.
Perhaps me not sufficiently understanding the difference between all
possible meanings of "expand" vs "extend" ...
Jan
next prev parent reply other threads:[~2022-01-17 11:23 UTC|newest]
Thread overview: 24+ messages / expand[flat|nested] mbox.gz Atom feed top
2022-01-13 16:38 [PATCH 0/3] x86/spec-ctrl: Fix NMI race condition Andrew Cooper
2022-01-13 16:38 ` [PATCH 1/3] x86/msr: Split MSR_SPEC_CTRL handling Andrew Cooper
2022-01-14 11:03 ` Roger Pau Monné
2022-01-17 11:07 ` Jan Beulich
2022-01-17 11:24 ` Andrew Cooper
2022-01-17 11:54 ` Jan Beulich
2022-01-13 16:38 ` [PATCH 2/3] x86/spec-ctrl: Drop SPEC_CTRL_{ENTRY_FROM,EXIT_TO}_HVM Andrew Cooper
2022-01-14 11:42 ` Roger Pau Monné
2022-01-14 11:49 ` Andrew Cooper
2022-01-17 11:22 ` Jan Beulich [this message]
2022-01-17 11:41 ` Andrew Cooper
2022-01-17 11:57 ` Jan Beulich
2022-01-13 16:38 ` [PATCH 3/3] x86/spec-ctrl: Fix NMI race condition with VT-x MSR_SPEC_CTRL handling Andrew Cooper
2022-01-14 12:50 ` Roger Pau Monné
2022-01-14 13:08 ` Andrew Cooper
2022-01-14 13:43 ` Roger Pau Monné
2022-01-14 13:49 ` Andrew Cooper
2022-01-14 14:14 ` Andrew Cooper
2022-01-14 14:41 ` Andrew Cooper
2022-01-17 9:21 ` Jan Beulich
2022-01-17 11:43 ` Andrew Cooper
2022-01-17 11:51 ` Jan Beulich
2022-01-17 17:23 ` Andrew Cooper
2022-01-18 7:57 ` Jan Beulich
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