Consolidate two bool parameters (write/fetch) of __linearize() into a
'u32 flags' parameter to make the function be more concise and future
extendable, i.e. to support Intel Linear Address Masking (LAM), which
allows high non-address bits of linear address to be used as metadata.
Define two flags to replace the two bools. A new flag will be added to
to support LAM to skip masking off metadata bits of linear address
under some conditions.
No functional change intended.
Signed-off-by: Binbin Wu <binbin.wu@xxxxxxxxxxxxxxx>
Reviewed-by: Chao Gao <chao.gao@xxxxxxxxx>
Acked-by: Kai Huang <kai.huang@xxxxxxxxx>
---
arch/x86/kvm/emulate.c | 19 ++++++++++---------
arch/x86/kvm/kvm_emulate.h | 4 ++++
2 files changed, 14 insertions(+), 9 deletions(-)
diff --git a/arch/x86/kvm/emulate.c b/arch/x86/kvm/emulate.c
index 936a397a08cd..e89afc39e56f 100644
--- a/arch/x86/kvm/emulate.c
+++ b/arch/x86/kvm/emulate.c
@@ -687,8 +687,8 @@ static unsigned insn_alignment(struct x86_emulate_ctxt *ctxt, unsigned size)
static __always_inline int __linearize(struct x86_emulate_ctxt *ctxt,
struct segmented_address addr,
unsigned *max_size, unsigned size,
- bool write, bool fetch,
- enum x86emul_mode mode, ulong *linear)
+ enum x86emul_mode mode, ulong *linear,
+ u32 flags)
{
struct desc_struct desc;
bool usable;
@@ -718,10 +718,10 @@ static __always_inline int __linearize(struct x86_emulate_ctxt *ctxt,
goto bad;
/* code segment in protected mode or read-only data segment */
if ((((ctxt->mode != X86EMUL_MODE_REAL) && (desc.type & 8))
- || !(desc.type & 2)) && write)
+ || !(desc.type & 2)) && (flags & X86EMUL_F_WRITE))
goto bad;
/* unreadable code segment */
- if (!fetch && (desc.type & 8) && !(desc.type & 2))
+ if (!(flags & X86EMUL_F_FETCH) && (desc.type & 8) && !(desc.type & 2))
goto bad;
lim = desc_limit_scaled(&desc);
if (!(desc.type & 8) && (desc.type & 4)) {
@@ -757,8 +757,8 @@ static int linearize(struct x86_emulate_ctxt *ctxt,
ulong *linear)
{
unsigned max_size;
- return __linearize(ctxt, addr, &max_size, size, write, false,
- ctxt->mode, linear);
+ return __linearize(ctxt, addr, &max_size, size, ctxt->mode, linear,
+ write ? X86EMUL_F_WRITE : 0);
}
static inline int assign_eip(struct x86_emulate_ctxt *ctxt, ulong dst)
@@ -771,7 +771,8 @@ static inline int assign_eip(struct x86_emulate_ctxt *ctxt, ulong dst)
if (ctxt->op_bytes != sizeof(unsigned long))
addr.ea = dst & ((1UL << (ctxt->op_bytes << 3)) - 1);
- rc = __linearize(ctxt, addr, &max_size, 1, false, true, ctxt->mode, &linear);
+ rc = __linearize(ctxt, addr, &max_size, 1, ctxt->mode, &linear,
+ X86EMUL_F_FETCH);
if (rc == X86EMUL_CONTINUE)
ctxt->_eip = addr.ea;
return rc;
@@ -907,8 +908,8 @@ static int __do_insn_fetch_bytes(struct x86_emulate_ctxt *ctxt, int op_size)
* boundary check itself. Instead, we use max_size to check
* against op_size.
*/
- rc = __linearize(ctxt, addr, &max_size, 0, false, true, ctxt->mode,
- &linear);
+ rc = __linearize(ctxt, addr, &max_size, 0, ctxt->mode, &linear,
+ X86EMUL_F_FETCH);
if (unlikely(rc != X86EMUL_CONTINUE))
return rc;
diff --git a/arch/x86/kvm/kvm_emulate.h b/arch/x86/kvm/kvm_emulate.h
index ab65f3a47dfd..5b9ec610b2cb 100644
--- a/arch/x86/kvm/kvm_emulate.h
+++ b/arch/x86/kvm/kvm_emulate.h
@@ -88,6 +88,10 @@ struct x86_instruction_info {
#define X86EMUL_IO_NEEDED 5 /* IO is needed to complete emulation */
#define X86EMUL_INTERCEPTED 6 /* Intercepted by nested VMCB/VMCS */
+/* x86-specific emulation flags */
+#define X86EMUL_F_FETCH BIT(0)
+#define X86EMUL_F_WRITE BIT(1)
+
struct x86_emulate_ops {
void (*vm_bugged)(struct x86_emulate_ctxt *ctxt);
/*
--
2.25.1
