From b85b9ee9259917f248ee1507d7d1f575f4fc27dd Mon Sep 17 00:00:00 2001 From: Rusty Russell Date: Sun, 9 Sep 2007 14:12:54 +0300 Subject: [PATCH] KVM: Clean up unloved invlpg emulation 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 Signed-off-by: Avi Kivity --- drivers/kvm/kvm.h | 2 -- drivers/kvm/svm.c | 2 -- drivers/kvm/x86_emulate.c | 16 +++------------- 3 files changed, 3 insertions(+), 17 deletions(-) diff --git a/drivers/kvm/kvm.h b/drivers/kvm/kvm.h index 7c353524af..9bf9ac6389 100644 --- a/drivers/kvm/kvm.h +++ b/drivers/kvm/kvm.h @@ -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); 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; struct page *gfn_to_page(struct kvm *kvm, gfn_t gfn); diff --git a/drivers/kvm/svm.c b/drivers/kvm/svm.c index dbd4e813cb..e51f6b7f8f 100644 --- a/drivers/kvm/svm.c +++ b/drivers/kvm/svm.c @@ -376,8 +376,6 @@ static __init int svm_hardware_setup(void) void *iopm_va, *msrpm_va; int r; - kvm_emulator_want_group7_invlpg(); - iopm_pages = alloc_pages(GFP_KERNEL, IOPM_ALLOC_ORDER); if (!iopm_pages) diff --git a/drivers/kvm/x86_emulate.c b/drivers/kvm/x86_emulate.c index 7439b3422e..342594d78d 100644 --- a/drivers/kvm/x86_emulate.c +++ b/drivers/kvm/x86_emulate.c @@ -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 }; -/* - * 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. */ struct operand { enum { OP_REG, OP_MEM, OP_IMM } type; @@ -791,6 +778,9 @@ done_prefixes: goto srcmem_common; case SrcMem: 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: src.type = OP_MEM; src.ptr = (unsigned long *)cr2; -- 2.39.5