* Abstract (X86_CR4_SMEP | X86_CR4_SMAP) behind XEN_CR4_PV32_BITS to avoid
opencoding the invidial bits which are fixed up behind a 32bit PV guests
back.
* In the debug case, perform the the AND and CMP on 64bit values rather than
32bit values, to match the logic in then non-debug case.
* Show cr4_pv32_mask in the BUG register dump
Signed-off-by: Andrew Cooper <andrew.coop...@citrix.com>
---
CC: Jan Beulich <jbeul...@suse.com>
CC: Wei Liu <wei.l...@citrix.com>
---
xen/arch/x86/setup.c | 2 +-
xen/arch/x86/x86_64/compat/entry.S | 8 +++++---
xen/include/asm-x86/processor.h | 2 ++
3 files changed, 8 insertions(+), 4 deletions(-)
diff --git a/xen/arch/x86/setup.c b/xen/arch/x86/setup.c
index 4c2d01a..de682e7 100644
--- a/xen/arch/x86/setup.c
+++ b/xen/arch/x86/setup.c
@@ -1400,7 +1400,7 @@ void __init noreturn __start_xen(unsigned long mbi_p)
if ( cpu_has_smap )
set_in_cr4(X86_CR4_SMAP);
- cr4_pv32_mask = mmu_cr4_features & (X86_CR4_SMEP | X86_CR4_SMAP);
+ cr4_pv32_mask = mmu_cr4_features & XEN_CR4_PV32_BITS;
if ( cpu_has_fsgsbase )
set_in_cr4(X86_CR4_FSGSBASE);
diff --git a/xen/arch/x86/x86_64/compat/entry.S
b/xen/arch/x86/x86_64/compat/entry.S
index dbc3984..ee72ece 100644
--- a/xen/arch/x86/x86_64/compat/entry.S
+++ b/xen/arch/x86/x86_64/compat/entry.S
@@ -204,7 +204,7 @@ ENTRY(cr4_pv32_restore)
push %rdx
GET_CPUINFO_FIELD(cr4, dx)
mov (%rdx), %rax
- test $X86_CR4_SMEP|X86_CR4_SMAP,%eax
+ test $XEN_CR4_PV32_BITS, %eax
jnz 0f
or cr4_pv32_mask(%rip), %rax
mov %rax, %cr4
@@ -215,9 +215,11 @@ ENTRY(cr4_pv32_restore)
#ifndef NDEBUG
/* Check that _all_ of the bits intended to be set actually are. */
mov %cr4, %rax
- and cr4_pv32_mask(%rip), %eax
- cmp cr4_pv32_mask(%rip), %eax
+ and cr4_pv32_mask(%rip), %rax
+ cmp cr4_pv32_mask(%rip), %rax
je 1f
+ /* Cause cr4_pv32_mask to be visible in the BUG register dump. */
+ mov cr4_pv32_mask(%rip), %rdx
BUG
1:
#endif
diff --git a/xen/include/asm-x86/processor.h b/xen/include/asm-x86/processor.h
index 4a6af0f..ddaaf2de 100644
--- a/xen/include/asm-x86/processor.h
+++ b/xen/include/asm-x86/processor.h
@@ -151,6 +151,8 @@
#define XEN_MINIMAL_CR4 (X86_CR4_PGE | X86_CR4_PAE)
+#define XEN_CR4_PV32_BITS (X86_CR4_SMEP|X86_CR4_SMAP)
+
#define XEN_SYSCALL_MASK (X86_EFLAGS_AC|X86_EFLAGS_VM|X86_EFLAGS_RF| \
X86_EFLAGS_NT|X86_EFLAGS_DF|X86_EFLAGS_IF| \
X86_EFLAGS_TF)
--
2.1.4
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