| Message ID | 20230913202758.508225-2-andrew.cooper3@citrix.com (mailing list archive) |
|---|---|
| State | Superseded |
| Headers | show |
| Series | x86/spec-ctrl: AMD DIV fix, and VERW prerequisite bugfixes | expand |
On 13.09.2023 22:27, Andrew Cooper wrote: > c/s 3fffaf9c13e9 ("x86/entry: Avoid using alternatives in NMI/#MC paths") > dropped the only user, leaving behind the (incorrect) implication that Xen had > split exit paths. > > Delete the unused SPEC_CTRL_EXIT_TO_XEN and rename SPEC_CTRL_EXIT_TO_XEN_IST > to SPEC_CTRL_EXIT_TO_XEN for consistency. > > No functional change. > > Signed-off-by: Andrew Cooper <andrew.cooper3@citrix.com> Reviewed-by: Jan Beulich <jbeulich@suse.com> albeit ... > @@ -256,11 +255,6 @@ > ALTERNATIVE "", __stringify(DO_SPEC_CTRL_ENTRY maybexen=1), \ > X86_FEATURE_SC_MSR_PV > > -/* Use when exiting to Xen context. */ > -#define SPEC_CTRL_EXIT_TO_XEN \ > - ALTERNATIVE "", \ > - DO_SPEC_CTRL_EXIT_TO_XEN, X86_FEATURE_SC_MSR_PV > - > /* Use when exiting to PV guest context. */ > #define SPEC_CTRL_EXIT_TO_PV \ > ALTERNATIVE "", \ > @@ -328,7 +322,7 @@ UNLIKELY_DISPATCH_LABEL(\@_serialise): > .endm > > /* Use when exiting to Xen in IST context. */ > -.macro SPEC_CTRL_EXIT_TO_XEN_IST > +.macro SPEC_CTRL_EXIT_TO_XEN ... with the comment her updated (either by dropping "in IST" or by explicitly mentioning both cases). Jan
On 14/09/2023 7:56 am, Jan Beulich wrote: > On 13.09.2023 22:27, Andrew Cooper wrote: >> c/s 3fffaf9c13e9 ("x86/entry: Avoid using alternatives in NMI/#MC paths") >> dropped the only user, leaving behind the (incorrect) implication that Xen had >> split exit paths. >> >> Delete the unused SPEC_CTRL_EXIT_TO_XEN and rename SPEC_CTRL_EXIT_TO_XEN_IST >> to SPEC_CTRL_EXIT_TO_XEN for consistency. >> >> No functional change. >> >> Signed-off-by: Andrew Cooper <andrew.cooper3@citrix.com> > Reviewed-by: Jan Beulich <jbeulich@suse.com> > albeit ... > >> @@ -256,11 +255,6 @@ >> ALTERNATIVE "", __stringify(DO_SPEC_CTRL_ENTRY maybexen=1), \ >> X86_FEATURE_SC_MSR_PV >> >> -/* Use when exiting to Xen context. */ >> -#define SPEC_CTRL_EXIT_TO_XEN \ >> - ALTERNATIVE "", \ >> - DO_SPEC_CTRL_EXIT_TO_XEN, X86_FEATURE_SC_MSR_PV >> - >> /* Use when exiting to PV guest context. */ >> #define SPEC_CTRL_EXIT_TO_PV \ >> ALTERNATIVE "", \ >> @@ -328,7 +322,7 @@ UNLIKELY_DISPATCH_LABEL(\@_serialise): >> .endm >> >> /* Use when exiting to Xen in IST context. */ >> -.macro SPEC_CTRL_EXIT_TO_XEN_IST >> +.macro SPEC_CTRL_EXIT_TO_XEN > ... with the comment her updated (either by dropping "in IST" or by > explicitly mentioning both cases). The comment is rewritten from scratch in patch 4. I'm not moving that rewrite to here, and the comment isn't technically wrong to begin with, but I suppose I can drop the IST part. Just means more churn. ~Andrew
diff --git a/xen/arch/x86/include/asm/spec_ctrl_asm.h b/xen/arch/x86/include/asm/spec_ctrl_asm.h index f48f9e75e8dc..14ec40e8d32f 100644 --- a/xen/arch/x86/include/asm/spec_ctrl_asm.h +++ b/xen/arch/x86/include/asm/spec_ctrl_asm.h @@ -67,7 +67,6 @@ * - SPEC_CTRL_ENTRY_FROM_PV * - SPEC_CTRL_ENTRY_FROM_INTR * - SPEC_CTRL_ENTRY_FROM_INTR_IST - * - SPEC_CTRL_EXIT_TO_XEN_IST * - SPEC_CTRL_EXIT_TO_XEN * - SPEC_CTRL_EXIT_TO_PV * @@ -256,11 +255,6 @@ ALTERNATIVE "", __stringify(DO_SPEC_CTRL_ENTRY maybexen=1), \ X86_FEATURE_SC_MSR_PV -/* Use when exiting to Xen context. */ -#define SPEC_CTRL_EXIT_TO_XEN \ - ALTERNATIVE "", \ - DO_SPEC_CTRL_EXIT_TO_XEN, X86_FEATURE_SC_MSR_PV - /* Use when exiting to PV guest context. */ #define SPEC_CTRL_EXIT_TO_PV \ ALTERNATIVE "", \ @@ -328,7 +322,7 @@ UNLIKELY_DISPATCH_LABEL(\@_serialise): .endm /* Use when exiting to Xen in IST context. */ -.macro SPEC_CTRL_EXIT_TO_XEN_IST +.macro SPEC_CTRL_EXIT_TO_XEN /* * Requires %rbx=stack_end * Clobbers %rax, %rcx, %rdx diff --git a/xen/arch/x86/x86_64/entry.S b/xen/arch/x86/x86_64/entry.S index 81dd2c74b876..a1c860f56949 100644 --- a/xen/arch/x86/x86_64/entry.S +++ b/xen/arch/x86/x86_64/entry.S @@ -673,7 +673,7 @@ UNLIKELY_START(ne, exit_cr3) UNLIKELY_END(exit_cr3) /* WARNING! `ret`, `call *`, `jmp *` not safe beyond this point. */ - SPEC_CTRL_EXIT_TO_XEN_IST /* Req: %rbx=end, Clob: acd */ + SPEC_CTRL_EXIT_TO_XEN /* Req: %rbx=end, Clob: acd */ RESTORE_ALL adj=8 iretq
c/s 3fffaf9c13e9 ("x86/entry: Avoid using alternatives in NMI/#MC paths") dropped the only user, leaving behind the (incorrect) implication that Xen had split exit paths. Delete the unused SPEC_CTRL_EXIT_TO_XEN and rename SPEC_CTRL_EXIT_TO_XEN_IST to SPEC_CTRL_EXIT_TO_XEN for consistency. No functional change. Signed-off-by: Andrew Cooper <andrew.cooper3@citrix.com> --- CC: Jan Beulich <JBeulich@suse.com> CC: Roger Pau Monné <roger.pau@citrix.com> CC: Wei Liu <wl@xen.org> --- xen/arch/x86/include/asm/spec_ctrl_asm.h | 8 +------- xen/arch/x86/x86_64/entry.S | 2 +- 2 files changed, 2 insertions(+), 8 deletions(-) base-commit: 6aa25c32180ab59081c73bae4c568367d9133a1f