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KVM: Clean up unloved invlpg emulation

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invlpg shouldn't fetch the "src" address, since it may not be valid,
however SVM's "solution" which neuters emulation of all group 7
instruction is horrible and breaks kvm-lite.  The simplest fix is to
put a special check in for invlpg.

Signed-off-by: Rusty Russell <rusty@rustcorp.com.au>
Signed-off-by: Avi Kivity <avi@qumranet.com>
This commit is contained in:
Rusty Russell
2007-09-09 14:12:54 +03:00
committed by Avi Kivity
parent c9a1185c94
commit b85b9ee925
3 changed files with 3 additions and 17 deletions
Download Patch File Download Diff File Expand all files Collapse all files

2
drivers/kvm/kvm.h
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@@ -539,8 +539,6 @@ static inline int is_error_hpa(hpa_t hpa) { return hpa >> HPA_MSB; }
hpa_t gva_to_hpa(struct kvm_vcpu *vcpu, gva_t gva); hpa_t gva_to_hpa(struct kvm_vcpu *vcpu, gva_t gva);
struct page *gva_to_page(struct kvm_vcpu *vcpu, gva_t gva); struct page *gva_to_page(struct kvm_vcpu *vcpu, gva_t gva);
void kvm_emulator_want_group7_invlpg(void);
extern hpa_t bad_page_address; extern hpa_t bad_page_address;
struct page *gfn_to_page(struct kvm *kvm, gfn_t gfn); struct page *gfn_to_page(struct kvm *kvm, gfn_t gfn);

2
drivers/kvm/svm.c
View File

@@ -376,8 +376,6 @@ static __init int svm_hardware_setup(void)
void *iopm_va, *msrpm_va; void *iopm_va, *msrpm_va;
int r; int r;
kvm_emulator_want_group7_invlpg();
iopm_pages = alloc_pages(GFP_KERNEL, IOPM_ALLOC_ORDER); iopm_pages = alloc_pages(GFP_KERNEL, IOPM_ALLOC_ORDER);
if (!iopm_pages) if (!iopm_pages)

16
drivers/kvm/x86_emulate.c
View File

@@ -213,19 +213,6 @@ static u16 twobyte_table[256] = {
0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0
}; };
/*
* Tell the emulator that of the Group 7 instructions (sgdt, lidt, etc.) we
* are interested only in invlpg and not in any of the rest.
*
* invlpg is a special instruction in that the data it references may not
* be mapped.
*/
void kvm_emulator_want_group7_invlpg(void)
{
twobyte_table[1] &= ~SrcMem;
}
EXPORT_SYMBOL_GPL(kvm_emulator_want_group7_invlpg);
/* Type, address-of, and value of an instruction's operand. */ /* Type, address-of, and value of an instruction's operand. */
struct operand { struct operand {
enum { OP_REG, OP_MEM, OP_IMM } type; enum { OP_REG, OP_MEM, OP_IMM } type;
@@ -791,6 +778,9 @@ done_prefixes:
goto srcmem_common; goto srcmem_common;
case SrcMem: case SrcMem:
src.bytes = (d & ByteOp) ? 1 : op_bytes; src.bytes = (d & ByteOp) ? 1 : op_bytes;
/* Don't fetch the address for invlpg: it could be unmapped. */
if (twobyte && b == 0x01 && modrm_reg == 7)
break;
srcmem_common: srcmem_common:
src.type = OP_MEM; src.type = OP_MEM;
src.ptr = (unsigned long *)cr2; src.ptr = (unsigned long *)cr2;