* [PATCH v4 2/3] kvm-unit-tests: Add a func to run instruction in emulator
2013-06-20 14:36 [PATCH v4 1/3] kvm-unit-tests: Add memcpy to lib/string.c Arthur Chunqi Li
@ 2013-06-20 14:36 ` Arthur Chunqi Li
2013-06-20 14:36 ` [PATCH v4 3/3] kvm-unit-tests: Change two cases to use trap_emulator Arthur Chunqi Li
2013-06-21 15:01 ` [PATCH v4 1/3] kvm-unit-tests: Add memcpy to lib/string.c Paolo Bonzini
2 siblings, 0 replies; 4+ messages in thread
From: Arthur Chunqi Li @ 2013-06-20 14:36 UTC (permalink / raw)
To: kvm; +Cc: gleb, pbonzini, jan.kiszka, Arthur Chunqi Li
Add a function trap_emulator to run an instruction in emulator.
Set inregs first (%rax is invalid because it is used as return
address), put instruction codec in alt_insn and call func with
alt_insn_length. Get results in outregs.
Signed-off-by: Arthur Chunqi Li <yzt356@gmail.com>
---
x86/emulator.c | 95 ++++++++++++++++++++++++++++++++++++++++++++++++++++++++
1 file changed, 95 insertions(+)
diff --git a/x86/emulator.c b/x86/emulator.c
index 96576e5..876ee5a 100644
--- a/x86/emulator.c
+++ b/x86/emulator.c
@@ -11,6 +11,20 @@ int fails, tests;
static int exceptions;
+struct regs {
+ u64 rax, rbx, rcx, rdx;
+ u64 rsi, rdi, rsp, rbp;
+ u64 r8, r9, r10, r11;
+ u64 r12, r13, r14, r15;
+ u64 rip, rflags;
+};
+struct regs inregs, outregs, save;
+
+struct insn_desc {
+ u64 ptr;
+ size_t len;
+};
+
void report(const char *name, int result)
{
++tests;
@@ -685,6 +699,87 @@ static void test_shld_shrd(u32 *mem)
report("shrd (cl)", *mem == ((0x12345678 >> 3) | (5u << 29)));
}
+#define INSN_XCHG_ALL \
+ "xchg %rax, 0+save \n\t" \
+ "xchg %rbx, 8+save \n\t" \
+ "xchg %rcx, 16+save \n\t" \
+ "xchg %rdx, 24+save \n\t" \
+ "xchg %rsi, 32+save \n\t" \
+ "xchg %rdi, 40+save \n\t" \
+ "xchg %rsp, 48+save \n\t" \
+ "xchg %rbp, 56+save \n\t" \
+ "xchg %r8, 64+save \n\t" \
+ "xchg %r9, 72+save \n\t" \
+ "xchg %r10, 80+save \n\t" \
+ "xchg %r11, 88+save \n\t" \
+ "xchg %r12, 96+save \n\t" \
+ "xchg %r13, 104+save \n\t" \
+ "xchg %r14, 112+save \n\t" \
+ "xchg %r15, 120+save \n\t"
+
+asm(
+ ".align 4096\n\t"
+ "insn_page:\n\t"
+ "ret\n\t"
+ "pushf\n\t"
+ "push 136+save \n\t"
+ "popf \n\t"
+ INSN_XCHG_ALL
+ "test_insn:\n\t"
+ "in (%dx),%al\n\t"
+ ".skip 31, 0x90\n\t"
+ "test_insn_end:\n\t"
+ INSN_XCHG_ALL
+ "pushf \n\t"
+ "pop 136+save \n\t"
+ "popf \n\t"
+ "ret \n\t"
+ "insn_page_end:\n\t"
+ ".align 4096\n\t"
+);
+
+#define MK_INSN(name, str) \
+ asm ( \
+ ".pushsection .data.insn \n\t" \
+ "insn_" #name ": \n\t" \
+ ".quad 1001f, 1002f - 1001f \n\t" \
+ ".popsection \n\t" \
+ ".pushsection .text.insn, \"ax\" \n\t" \
+ "1001: \n\t" \
+ "insn_code_" #name ": " str " \n\t" \
+ "1002: \n\t" \
+ ".popsection" \
+ ); \
+ extern struct insn_desc insn_##name;
+
+static void trap_emulator(uint64_t *mem, void *alt_insn_page,
+ struct insn_desc *alt_insn)
+{
+ ulong *cr3 = (ulong *)read_cr3();
+ void *insn_ram;
+ extern u8 insn_page[], test_insn[];
+
+ insn_ram = vmap(virt_to_phys(insn_page), 4096);
+ memcpy(alt_insn_page, insn_page, 4096);
+ memcpy(alt_insn_page + (test_insn - insn_page),
+ (void *)(alt_insn->ptr), alt_insn->len);
+ save = inregs;
+
+ /* Load the code TLB with insn_page, but point the page tables at
+ alt_insn_page (and keep the data TLB clear, for AMD decode assist).
+ This will make the CPU trap on the insn_page instruction but the
+ hypervisor will see alt_insn_page. */
+ install_page(cr3, virt_to_phys(insn_page), insn_ram);
+ invlpg(insn_ram);
+ /* Load code TLB */
+ asm volatile("call *%0" : : "r"(insn_ram));
+ install_page(cr3, virt_to_phys(alt_insn_page), insn_ram);
+ /* Trap, let hypervisor emulate at alt_insn_page */
+ asm volatile("call *%0": : "r"(insn_ram+1));
+
+ outregs = save;
+}
+
static void advance_rip_by_3_and_note_exception(struct ex_regs *regs)
{
++exceptions;
--
1.7.9.5
^ permalink raw reply related [flat|nested] 4+ messages in thread* [PATCH v4 3/3] kvm-unit-tests: Change two cases to use trap_emulator
2013-06-20 14:36 [PATCH v4 1/3] kvm-unit-tests: Add memcpy to lib/string.c Arthur Chunqi Li
2013-06-20 14:36 ` [PATCH v4 2/3] kvm-unit-tests: Add a func to run instruction in emulator Arthur Chunqi Li
@ 2013-06-20 14:36 ` Arthur Chunqi Li
2013-06-21 15:01 ` [PATCH v4 1/3] kvm-unit-tests: Add memcpy to lib/string.c Paolo Bonzini
2 siblings, 0 replies; 4+ messages in thread
From: Arthur Chunqi Li @ 2013-06-20 14:36 UTC (permalink / raw)
To: kvm; +Cc: gleb, pbonzini, jan.kiszka, Arthur Chunqi Li
Change two functions (test_mmx_movq_mf and test_movabs) using
unified trap_emulator.
Signed-off-by: Arthur Chunqi Li <yzt356@gmail.com>
---
x86/emulator.c | 70 ++++++++++++--------------------------------------------
1 file changed, 15 insertions(+), 55 deletions(-)
diff --git a/x86/emulator.c b/x86/emulator.c
index 876ee5a..68d2b93 100644
--- a/x86/emulator.c
+++ b/x86/emulator.c
@@ -789,38 +789,20 @@ static void advance_rip_by_3_and_note_exception(struct ex_regs *regs)
static void test_mmx_movq_mf(uint64_t *mem, uint8_t *insn_page,
uint8_t *alt_insn_page, void *insn_ram)
{
- uint16_t fcw = 0; // all exceptions unmasked
- ulong *cr3 = (ulong *)read_cr3();
-
- write_cr0(read_cr0() & ~6); // TS, EM
- // Place a trapping instruction in the page to trigger a VMEXIT
- insn_page[0] = 0x89; // mov %eax, (%rax)
- insn_page[1] = 0x00;
- insn_page[2] = 0x90; // nop
- insn_page[3] = 0xc3; // ret
- // Place the instruction we want the hypervisor to see in the alternate page
- alt_insn_page[0] = 0x0f; // movq %mm0, (%rax)
- alt_insn_page[1] = 0x7f;
- alt_insn_page[2] = 0x00;
- alt_insn_page[3] = 0xc3; // ret
+ uint16_t fcw = 0; /* all exceptions unmasked */
+ /* movq %mm0, (%rax) */
+ void *stack = alloc_page();
+ write_cr0(read_cr0() & ~6); /* TS, EM */
exceptions = 0;
handle_exception(MF_VECTOR, advance_rip_by_3_and_note_exception);
-
- // Load the code TLB with insn_page, but point the page tables at
- // alt_insn_page (and keep the data TLB clear, for AMD decode assist).
- // This will make the CPU trap on the insn_page instruction but the
- // hypervisor will see alt_insn_page.
- install_page(cr3, virt_to_phys(insn_page), insn_ram);
asm volatile("fninit; fldcw %0" : : "m"(fcw));
- asm volatile("fldz; fldz; fdivp"); // generate exception
- invlpg(insn_ram);
- // Load code TLB
- asm volatile("call *%0" : : "r"(insn_ram + 3));
- install_page(cr3, virt_to_phys(alt_insn_page), insn_ram);
- // Trap, let hypervisor emulate at alt_insn_page
- asm volatile("call *%0" : : "r"(insn_ram), "a"(mem));
- // exit MMX mode
+ asm volatile("fldz; fldz; fdivp"); /* generate exception */
+
+ MK_INSN(mmx_movq_mf, "movq %mm0, (%rax) \n\t");
+ inregs = (struct regs){ .rsp=(u64)stack+1024 };
+ trap_emulator(mem, alt_insn_page, &insn_mmx_movq_mf);
+ /* exit MMX mode */
asm volatile("fnclex; emms");
report("movq mmx generates #MF", exceptions == 1);
handle_exception(MF_VECTOR, 0);
@@ -829,33 +811,11 @@ static void test_mmx_movq_mf(uint64_t *mem, uint8_t *insn_page,
static void test_movabs(uint64_t *mem, uint8_t *insn_page,
uint8_t *alt_insn_page, void *insn_ram)
{
- uint64_t val = 0;
- ulong *cr3 = (ulong *)read_cr3();
-
- // Pad with RET instructions
- memset(insn_page, 0xc3, 4096);
- memset(alt_insn_page, 0xc3, 4096);
- // Place a trapping instruction in the page to trigger a VMEXIT
- insn_page[0] = 0x89; // mov %eax, (%rax)
- insn_page[1] = 0x00;
- // Place the instruction we want the hypervisor to see in the alternate
- // page. A buggy hypervisor will fetch a 32-bit immediate and return
- // 0xffffffffc3c3c3c3.
- alt_insn_page[0] = 0x48; // mov $0xc3c3c3c3c3c3c3c3, %rcx
- alt_insn_page[1] = 0xb9;
-
- // Load the code TLB with insn_page, but point the page tables at
- // alt_insn_page (and keep the data TLB clear, for AMD decode assist).
- // This will make the CPU trap on the insn_page instruction but the
- // hypervisor will see alt_insn_page.
- install_page(cr3, virt_to_phys(insn_page), insn_ram);
- // Load code TLB
- invlpg(insn_ram);
- asm volatile("call *%0" : : "r"(insn_ram + 3));
- // Trap, let hypervisor emulate at alt_insn_page
- install_page(cr3, virt_to_phys(alt_insn_page), insn_ram);
- asm volatile("call *%1" : "=c"(val) : "r"(insn_ram), "a"(mem), "c"(0));
- report("64-bit mov imm", val == 0xc3c3c3c3c3c3c3c3);
+ /* mov $0x9090909090909090, %rcx */
+ MK_INSN(movabs, "mov $0x9090909090909090, %rcx\n\t");
+ inregs = (struct regs){ 0 };
+ trap_emulator(mem, alt_insn_page, &insn_movabs);
+ report("64-bit mov imm2", outregs.rcx == 0x9090909090909090);
}
static void test_crosspage_mmio(volatile uint8_t *mem)
--
1.7.9.5
^ permalink raw reply related [flat|nested] 4+ messages in thread* Re: [PATCH v4 1/3] kvm-unit-tests: Add memcpy to lib/string.c
2013-06-20 14:36 [PATCH v4 1/3] kvm-unit-tests: Add memcpy to lib/string.c Arthur Chunqi Li
2013-06-20 14:36 ` [PATCH v4 2/3] kvm-unit-tests: Add a func to run instruction in emulator Arthur Chunqi Li
2013-06-20 14:36 ` [PATCH v4 3/3] kvm-unit-tests: Change two cases to use trap_emulator Arthur Chunqi Li
@ 2013-06-21 15:01 ` Paolo Bonzini
2 siblings, 0 replies; 4+ messages in thread
From: Paolo Bonzini @ 2013-06-21 15:01 UTC (permalink / raw)
To: Arthur Chunqi Li; +Cc: kvm, gleb, jan.kiszka
Il 20/06/2013 16:36, Arthur Chunqi Li ha scritto:
> Add memcpy(void *dest, const void *src, size_t n) to lib/string.c.
> This function acts the same as memcpy in libc.
>
> Signed-off-by: Arthur Chunqi Li <yzt356@gmail.com>
> ---
> lib/libcflat.h | 1 +
> lib/string.c | 12 ++++++++++++
> 2 files changed, 13 insertions(+)
>
> diff --git a/lib/libcflat.h b/lib/libcflat.h
> index 0875bd9..fadc33d 100644
> --- a/lib/libcflat.h
> +++ b/lib/libcflat.h
> @@ -50,6 +50,7 @@ extern int vsnprintf(char *buf, int size, const char *fmt, va_list va);
> extern void puts(const char *s);
>
> extern void *memset(void *s, int c, size_t n);
> +extern void *memcpy(void *dest, const void *src, size_t n);
>
> extern long atol(const char *ptr);
> #define ARRAY_SIZE(_a) (sizeof(_a)/sizeof((_a)[0]))
> diff --git a/lib/string.c b/lib/string.c
> index 9dc94a1..e798f86 100644
> --- a/lib/string.c
> +++ b/lib/string.c
> @@ -42,6 +42,18 @@ void *memset(void *s, int c, size_t n)
> return s;
> }
>
> +void *memcpy(void *dest, const void *src, size_t n)
> +{
> + size_t i;
> + char *a = dest;
> + char *b = src;
I added a const here and pushed the three patches.
Paolo
> +
> + for (i = 0; i < n; ++i)
> + a[i] = b[i];
> +
> + return dest;
> +}
> +
> long atol(const char *ptr)
> {
> long acc = 0;
>
^ permalink raw reply [flat|nested] 4+ messages in thread