# HG changeset patch
# User Keir Fraser <keir.fraser@xxxxxxxxxx>
# Date 1259234690 0
# Node ID 8a0f156487b0c90a75474a38dd238c3e7b7aa630
# Parent 44ea369eefc13145c082fd0e48d15e502b7cd5b9
x86: Always respect guest setting CR4.TSD
Also fix guest reads of CR4.
Signed-off-by: Keir Fraser <keir.fraser@xxxxxxxxxx>
---
xen/arch/x86/time.c | 2 +-
xen/arch/x86/traps.c | 22 ++++++++++++----------
2 files changed, 13 insertions(+), 11 deletions(-)
diff -r 44ea369eefc1 -r 8a0f156487b0 xen/arch/x86/time.c
--- a/xen/arch/x86/time.c Thu Nov 26 11:02:30 2009 +0000
+++ b/xen/arch/x86/time.c Thu Nov 26 11:24:50 2009 +0000
@@ -1640,7 +1640,7 @@ void pv_soft_rdtsc(struct vcpu *v, struc
if ( rdtscp )
regs->ecx =
- (d->arch.tsc_mode == TSC_MODE_PVRDTSCP) ? d->arch.incarnation :
0;
+ (d->arch.tsc_mode == TSC_MODE_PVRDTSCP) ? d->arch.incarnation : 0;
}
static int host_tsc_is_safe(void)
diff -r 44ea369eefc1 -r 8a0f156487b0 xen/arch/x86/traps.c
--- a/xen/arch/x86/traps.c Thu Nov 26 11:02:30 2009 +0000
+++ b/xen/arch/x86/traps.c Thu Nov 26 11:24:50 2009 +0000
@@ -2034,9 +2034,7 @@ static int emulate_privileged_op(struct
* are executable only from guest kernel mode (virtual ring 0).
*/
opcode = insn_fetch(u8, code_base, eip, code_limit);
- if ( !guest_kernel_mode(v, regs) &&
- (opcode != 0x1) && /* always emulate rdtscp */
- !((opcode == 0x31) && v->domain->arch.vtsc) )
+ if ( !guest_kernel_mode(v, regs) && (opcode != 0x1) && (opcode != 0x31) )
goto fail;
if ( lock && (opcode & ~3) != 0x20 )
@@ -2044,6 +2042,9 @@ static int emulate_privileged_op(struct
switch ( opcode )
{
case 0x1: /* RDTSCP */
+ if ( (v->arch.guest_context.ctrlreg[4] & X86_CR4_TSD) &&
+ !guest_kernel_mode(v, regs) )
+ goto fail;
if ( insn_fetch(u8, code_base, eip, code_limit) != 0xf9 )
goto fail;
pv_soft_rdtsc(v, regs, 1);
@@ -2093,12 +2094,7 @@ static int emulate_privileged_op(struct
break;
case 4: /* Read CR4 */
- /*
- * Guests can read CR4 to see what features Xen has enabled. We
- * therefore lie about PGE and PSE as they are unavailable to
- * guests.
- */
- *reg = read_cr4() & ~(X86_CR4_PGE|X86_CR4_PSE);
+ *reg = v->arch.guest_context.ctrlreg[4];
break;
default:
@@ -2297,7 +2293,13 @@ static int emulate_privileged_op(struct
}
case 0x31: /* RDTSC */
- pv_soft_rdtsc(v, regs, 0);
+ if ( (v->arch.guest_context.ctrlreg[4] & X86_CR4_TSD) &&
+ !guest_kernel_mode(v, regs) )
+ goto fail;
+ if ( v->domain->arch.vtsc )
+ pv_soft_rdtsc(v, regs, 0);
+ else
+ rdtsc(regs->eax, regs->edx);
break;
case 0x32: /* RDMSR */
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