diff options
Diffstat (limited to '0034-x86-spec-ctrl-Improve-all-SPEC_CTRL_-ENTER-EXIT-_-co.patch')
| -rw-r--r-- | 0034-x86-spec-ctrl-Improve-all-SPEC_CTRL_-ENTER-EXIT-_-co.patch | 106 |
1 files changed, 0 insertions, 106 deletions
diff --git a/0034-x86-spec-ctrl-Improve-all-SPEC_CTRL_-ENTER-EXIT-_-co.patch b/0034-x86-spec-ctrl-Improve-all-SPEC_CTRL_-ENTER-EXIT-_-co.patch deleted file mode 100644 index f360cbd..0000000 --- a/0034-x86-spec-ctrl-Improve-all-SPEC_CTRL_-ENTER-EXIT-_-co.patch +++ /dev/null @@ -1,106 +0,0 @@ -From ba023e93d0b1e60b80251bf080bab694efb9f8e3 Mon Sep 17 00:00:00 2001 -From: Andrew Cooper <andrew.cooper3@citrix.com> -Date: Wed, 30 Aug 2023 20:11:50 +0100 -Subject: [PATCH 34/55] x86/spec-ctrl: Improve all SPEC_CTRL_{ENTER,EXIT}_* - comments - -... to better explain how they're used. - -Doing so highlights that SPEC_CTRL_EXIT_TO_XEN is missing a VERW flush for the -corner case when e.g. an NMI hits late in an exit-to-guest path. - -Leave a TODO, which will be addressed in subsequent patches which arrange for -VERW flushing to be safe within SPEC_CTRL_EXIT_TO_XEN. - -Signed-off-by: Andrew Cooper <andrew.cooper3@citrix.com> -Reviewed-by: Jan Beulich <jbeulich@suse.com> -(cherry picked from commit 45f00557350dc7d0756551069803fc49c29184ca) ---- - xen/arch/x86/include/asm/spec_ctrl_asm.h | 36 ++++++++++++++++++++---- - 1 file changed, 31 insertions(+), 5 deletions(-) - -diff --git a/xen/arch/x86/include/asm/spec_ctrl_asm.h b/xen/arch/x86/include/asm/spec_ctrl_asm.h -index c6d5f2ad01..97c4db31cd 100644 ---- a/xen/arch/x86/include/asm/spec_ctrl_asm.h -+++ b/xen/arch/x86/include/asm/spec_ctrl_asm.h -@@ -230,7 +230,10 @@ - wrmsr - .endm - --/* Use after an entry from PV context (syscall/sysenter/int80/int82/etc). */ -+/* -+ * Used after an entry from PV context: SYSCALL, SYSENTER, INT, -+ * etc. There is always a guest speculation state in context. -+ */ - .macro SPEC_CTRL_ENTRY_FROM_PV - /* - * Requires %rsp=regs/cpuinfo, %rdx=0 -@@ -245,7 +248,11 @@ - X86_FEATURE_SC_MSR_PV - .endm - --/* Use in interrupt/exception context. May interrupt Xen or PV context. */ -+/* -+ * Used after an exception or maskable interrupt, hitting Xen or PV context. -+ * There will either be a guest speculation context, or (barring fatal -+ * exceptions) a well-formed Xen speculation context. -+ */ - .macro SPEC_CTRL_ENTRY_FROM_INTR - /* - * Requires %rsp=regs, %r14=stack_end, %rdx=0 -@@ -260,7 +267,10 @@ - X86_FEATURE_SC_MSR_PV - .endm - --/* Use when exiting to PV guest context. */ -+/* -+ * Used when exiting from any entry context, back to PV context. This -+ * includes from an IST entry which moved onto the primary stack. -+ */ - .macro SPEC_CTRL_EXIT_TO_PV - /* - * Requires %rax=spec_ctrl, %rsp=regs/info -@@ -272,7 +282,13 @@ - .endm - - /* -- * Use in IST interrupt/exception context. May interrupt Xen or PV context. -+ * Used after an IST entry hitting Xen or PV context. Special care is needed, -+ * because when hitting Xen context, there may not be a well-formed -+ * speculation context. (i.e. it can hit in the middle of -+ * SPEC_CTRL_{ENTRY,EXIT}_* regions.) -+ * -+ * An IST entry which hits PV context moves onto the primary stack and leaves -+ * via SPEC_CTRL_EXIT_TO_PV, *not* SPEC_CTRL_EXIT_TO_XEN. - */ - .macro SPEC_CTRL_ENTRY_FROM_INTR_IST - /* -@@ -331,7 +347,14 @@ UNLIKELY_DISPATCH_LABEL(\@_serialise): - UNLIKELY_END(\@_serialise) - .endm - --/* Use when exiting to Xen context. */ -+/* -+ * Use when exiting from any entry context, back to Xen context. This -+ * includes returning to other SPEC_CTRL_{ENTRY,EXIT}_* regions with an -+ * incomplete speculation context. -+ * -+ * Because we might have interrupted Xen beyond SPEC_CTRL_EXIT_TO_$GUEST, we -+ * need to treat this as if it were an EXIT_TO_$GUEST case too. -+ */ - .macro SPEC_CTRL_EXIT_TO_XEN - /* - * Requires %rbx=stack_end -@@ -356,6 +379,9 @@ UNLIKELY_DISPATCH_LABEL(\@_serialise): - wrmsr - - .L\@_skip_sc_msr: -+ -+ /* TODO VERW */ -+ - .endm - - #endif /* __ASSEMBLY__ */ --- -2.42.0 - |