From: Andrew Cooper <andrew.cooper3@citrix.com>
To: Jan Beulich <jbeulich@suse.com>
Cc: Xen-devel <xen-devel@lists.xenproject.org>,
"Wei Liu" <wl@xen.org>, "Roger Pau Monné" <roger.pau@citrix.com>
Subject: Re: [Xen-devel] [PATCH 4/4] x86/svm: Use named (bit)fields for task switch exit info
Date: Wed, 4 Dec 2019 20:04:49 +0000 [thread overview]
Message-ID: <d4fc4cfe-b4d0-5c26-12dc-df1631f8d49b@citrix.com> (raw)
In-Reply-To: <2d347b3a-7b2e-d28a-59d0-2206bc215206@suse.com>
On 04/12/2019 10:24, Jan Beulich wrote:
> On 04.12.2019 10:43, Andrew Cooper wrote:
>> Introduce vmcb.e1.* and vmcb.e2.* to provide names to fields in exitinfo{1,2}
>> respectively. Implement the task switch names for now, and clean up the
>> TASK_SWITCH handler.
> "e1" and "e2" look overly short - and hence possibly ambiguous -
> to me. Make them perhaps "ei1" and "ei2"?
Written on their own like that perhaps, but the ei[12] versions are
equally ambiguous.
However, they are only ever used with vmcb-> in code, so there is no
issue with ambiguity.
> Furthermore, seeing ...
>
>> @@ -2795,19 +2792,12 @@ void svm_vmexit_handler(struct cpu_user_regs *regs)
>> if ( insn_len < 0 && (insn_len = svm_get_task_switch_insn_len()) == 0 )
>> goto crash_or_fault;
>>
>> - if ( (vmcb->exitinfo2 >> 36) & 1 )
>> - reason = TSW_iret;
>> - else if ( (vmcb->exitinfo2 >> 38) & 1 )
>> - reason = TSW_jmp;
>> - else
>> - reason = TSW_call_or_int;
>> - if ( (vmcb->exitinfo2 >> 44) & 1 )
>> - errcode = (uint32_t)vmcb->exitinfo2;
>> -
>> - hvm_task_switch(vmcb->exitinfo1, reason, errcode, insn_len,
>> - (vmcb->exitinfo2 & (1ul << 48)) ? X86_EFLAGS_RF : 0);
>> + hvm_task_switch(vmcb->e1.task_switch.sel,
>> + vmcb->e2.task_switch.iret ? TSW_iret :
>> + vmcb->e2.task_switch.jmp ? TSW_jmp : TSW_call_or_int,
>> + vmcb->e2.task_switch.ev ? vmcb->e2.task_switch.ec : -1,
>> + insn_len, vmcb->e2.task_switch.rf ? X86_EFLAGS_RF : 0);
> ... this, wouldn't it make sense to simply have "ei" covering both
> parts, no longer making it a requirement to use (and hence look up)
> the numeric suffixes at use sites?
Net delta is:
diff --git a/xen/include/asm-x86/hvm/svm/vmcb.h
b/xen/include/asm-x86/hvm/svm/vmcb.h
index 02b5e86b49..864618ccf9 100644
--- a/xen/include/asm-x86/hvm/svm/vmcb.h
+++ b/xen/include/asm-x86/hvm/svm/vmcb.h
@@ -419,17 +419,15 @@ struct vmcb_struct {
u64 interrupt_shadow; /* offset 0x68 */
u64 exitcode; /* offset 0x70 */
union {
- u64 exitinfo1; /* offset 0x78 */
+ struct {
+ uint64_t exitinfo1; /* offset 0x78 */
+ uint64_t exitinfo2; /* offset 0x80 */
+ };
union {
struct {
uint16_t sel;
- } task_switch;
- } e1;
- };
- union {
- u64 exitinfo2; /* offset 0x80 */
- union {
- struct {
+ uint64_t :48;
+
uint32_t ec;
uint32_t :4;
bool iret:1;
@@ -440,7 +438,7 @@ struct vmcb_struct {
uint32_t :3;
bool rf:1;
} task_switch;
- } e2;
+ } ei;
};
intinfo_t exitintinfo; /* offset 0x88 */
u64 _np_enable; /* offset 0x90 - cleanbit 4 */
LGTM.
~Andrew
_______________________________________________
Xen-devel mailing list
Xen-devel@lists.xenproject.org
https://lists.xenproject.org/mailman/listinfo/xen-devel
next prev parent reply other threads:[~2019-12-04 20:05 UTC|newest]
Thread overview: 18+ messages / expand[flat|nested] mbox.gz Atom feed top
2019-12-04 9:43 [Xen-devel] [PATCH 0/4] x86/svm: (Post TASK_SWITCH) cleanup Andrew Cooper
2019-12-04 9:43 ` [Xen-devel] [PATCH 1/4] x86/svm: Clean up construct_vmcb() Andrew Cooper
2019-12-04 10:06 ` Jan Beulich
2019-12-04 19:21 ` Andrew Cooper
2019-12-04 9:43 ` [Xen-devel] [PATCH 2/4] x86/svm: Don't shadow variables in svm_vmexit_handler() Andrew Cooper
2019-12-04 10:10 ` Jan Beulich
2019-12-04 9:43 ` [Xen-devel] [PATCH 3/4] x86/svm: Clean up intinfo_t variables Andrew Cooper
2019-12-04 10:19 ` Jan Beulich
2019-12-04 19:22 ` Andrew Cooper
2019-12-04 19:38 ` Andrew Cooper
2019-12-05 9:11 ` Jan Beulich
2019-12-05 12:33 ` Andrew Cooper
2019-12-04 9:43 ` [Xen-devel] [PATCH 4/4] x86/svm: Use named (bit)fields for task switch exit info Andrew Cooper
2019-12-04 10:24 ` Jan Beulich
2019-12-04 20:04 ` Andrew Cooper [this message]
2019-12-05 9:05 ` Jan Beulich
2019-12-05 10:51 ` [Xen-devel] [PATCH 5/4] x86/svm: Minor cleanup to start_svm() Andrew Cooper
2019-12-05 10:53 ` Jan Beulich
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=d4fc4cfe-b4d0-5c26-12dc-df1631f8d49b@citrix.com \
--to=andrew.cooper3@citrix.com \
--cc=jbeulich@suse.com \
--cc=roger.pau@citrix.com \
--cc=wl@xen.org \
--cc=xen-devel@lists.xenproject.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).