[kvm-unit-tests PATCH v3 19/27] svm: rewerite vm entry macros

[Maxim Levitsky <mlevitsk@redhat.com>]

Make SVM VM entry macros to not use harcode regs label
and also simplify them as much as possible

Signed-off-by: Maxim Levitsky <mlevitsk@redhat.com>
---
 lib/x86/svm_lib.h | 71 +++++++++++++++++++++++++++++++++++++++++++++++
 x86/svm.c         | 58 ++++++++++++--------------------------
 x86/svm.h         | 70 ++--------------------------------------------
 x86/svm_tests.c   | 24 ++++++++++------
 4 files changed, 106 insertions(+), 117 deletions(-)

diff --git a/lib/x86/svm_lib.h b/lib/x86/svm_lib.h
index 3bb098dc..f9c2b352 100644
--- a/lib/x86/svm_lib.h
+++ b/lib/x86/svm_lib.h
@@ -66,4 +66,75 @@ u8 *svm_get_io_bitmap(void);
 #define MSR_BITMAP_SIZE 8192
 
 
+struct svm_gprs {
+	u64 rax;
+	u64 rbx;
+	u64 rcx;
+	u64 rdx;
+	u64 rbp;
+	u64 rsi;
+	u64 rdi;
+	u64 r8;
+	u64 r9;
+	u64 r10;
+	u64 r11;
+	u64 r12;
+	u64 r13;
+	u64 r14;
+	u64 r15;
+	u64 rsp;
+};
+
+#define SWAP_GPRS \
+	"xchg %%rbx, 0x08(%%rax)\n"           \
+	"xchg %%rcx, 0x10(%%rax)\n"           \
+	"xchg %%rdx, 0x18(%%rax)\n"           \
+	"xchg %%rbp, 0x20(%%rax)\n"           \
+	"xchg %%rsi, 0x28(%%rax)\n"           \
+	"xchg %%rdi, 0x30(%%rax)\n"           \
+	"xchg %%r8,  0x38(%%rax)\n"           \
+	"xchg %%r9,  0x40(%%rax)\n"           \
+	"xchg %%r10, 0x48(%%rax)\n"           \
+	"xchg %%r11, 0x50(%%rax)\n"           \
+	"xchg %%r12, 0x58(%%rax)\n"           \
+	"xchg %%r13, 0x60(%%rax)\n"           \
+	"xchg %%r14, 0x68(%%rax)\n"           \
+	"xchg %%r15, 0x70(%%rax)\n"           \
+	\
+
+
+#define __SVM_VMRUN(vmcb, regs, label)        \
+{                                             \
+	u32 dummy;                            \
+\
+	(vmcb)->save.rax = (regs)->rax;       \
+	(vmcb)->save.rsp = (regs)->rsp;       \
+\
+	asm volatile (                        \
+		"vmload %%rax\n"              \
+		"push %%rbx\n"                \
+		"push %%rax\n"                \
+		"mov %%rbx, %%rax\n"          \
+		SWAP_GPRS                     \
+		"pop %%rax\n"                 \
+		".global " label "\n"         \
+		label ": vmrun %%rax\n"       \
+		"vmsave %%rax\n"              \
+		"pop %%rax\n"                 \
+		SWAP_GPRS                     \
+		: "=a"(dummy),                \
+		  "=b"(dummy)                 \
+		: "a" (virt_to_phys(vmcb)),   \
+		  "b"(regs)                   \
+		/* clobbers*/                 \
+		: "memory"                    \
+	);                                    \
+\
+	(regs)->rax = (vmcb)->save.rax;       \
+	(regs)->rsp = (vmcb)->save.rsp;       \
+}
+
+#define SVM_VMRUN(vmcb, regs) \
+	__SVM_VMRUN(vmcb, regs, "vmrun_dummy_label_%=")
+
 #endif /* SRC_LIB_X86_SVM_LIB_H_ */
diff --git a/x86/svm.c b/x86/svm.c
index 5e2c3a83..220bce66 100644
--- a/x86/svm.c
+++ b/x86/svm.c
@@ -76,16 +76,13 @@ static void test_thunk(struct svm_test *test)
 	vmmcall();
 }
 
-struct regs regs;
+static struct svm_gprs regs;
 
-struct regs get_regs(void)
+struct svm_gprs *get_regs(void)
 {
-	return regs;
+	return &regs;
 }
 
-// rax handled specially below
-
-
 struct svm_test *v2_test;
 
 
@@ -94,16 +91,10 @@ u64 guest_stack[10000];
 int __svm_vmrun(u64 rip)
 {
 	vmcb->save.rip = (ulong)rip;
-	vmcb->save.rsp = (ulong)(guest_stack + ARRAY_SIZE(guest_stack));
+	regs.rsp = (ulong)(guest_stack + ARRAY_SIZE(guest_stack));
 	regs.rdi = (ulong)v2_test;
 
-	asm volatile (
-		      ASM_PRE_VMRUN_CMD
-		      "vmrun %%rax\n\t"               \
-		      ASM_POST_VMRUN_CMD
-		      :
-		      : "a" (virt_to_phys(vmcb))
-		      : "memory", "r15");
+	SVM_VMRUN(vmcb, &regs);
 
 	return (vmcb->control.exit_code);
 }
@@ -113,43 +104,28 @@ int svm_vmrun(void)
 	return __svm_vmrun((u64)test_thunk);
 }
 
-extern u8 vmrun_rip;
-
 static noinline void test_run(struct svm_test *test)
 {
-	u64 vmcb_phys = virt_to_phys(vmcb);
-
 	cli();
 	vmcb_ident(vmcb);
 
 	test->prepare(test);
 	guest_main = test->guest_func;
 	vmcb->save.rip = (ulong)test_thunk;
-	vmcb->save.rsp = (ulong)(guest_stack + ARRAY_SIZE(guest_stack));
+	regs.rsp = (ulong)(guest_stack + ARRAY_SIZE(guest_stack));
 	regs.rdi = (ulong)test;
 	do {
-		struct svm_test *the_test = test;
-		u64 the_vmcb = vmcb_phys;
-		asm volatile (
-			      "clgi;\n\t" // semi-colon needed for LLVM compatibility
-			      "sti \n\t"
-			      "call *%c[PREPARE_GIF_CLEAR](%[test]) \n \t"
-			      "mov %[vmcb_phys], %%rax \n\t"
-			      ASM_PRE_VMRUN_CMD
-			      ".global vmrun_rip\n\t"		\
-			      "vmrun_rip: vmrun %%rax\n\t"    \
-			      ASM_POST_VMRUN_CMD
-			      "cli \n\t"
-			      "stgi"
-			      : // inputs clobbered by the guest:
-				"=D" (the_test),            // first argument register
-				"=b" (the_vmcb)             // callee save register!
-			      : [test] "0" (the_test),
-				[vmcb_phys] "1"(the_vmcb),
-				[PREPARE_GIF_CLEAR] "i" (offsetof(struct svm_test, prepare_gif_clear))
-			      : "rax", "rcx", "rdx", "rsi",
-				"r8", "r9", "r10", "r11" , "r12", "r13", "r14", "r15",
-				"memory");
+
+		clgi();
+		sti();
+
+		test->prepare_gif_clear(test);
+
+		__SVM_VMRUN(vmcb, &regs, "vmrun_rip");
+
+		cli();
+		stgi();
+
 		++test->exits;
 	} while (!test->finished(test));
 	sti();
diff --git a/x86/svm.h b/x86/svm.h
index a4aabeb2..6f809ce3 100644
--- a/x86/svm.h
+++ b/x86/svm.h
@@ -23,26 +23,6 @@ struct svm_test {
 	bool on_vcpu_done;
 };
 
-struct regs {
-	u64 rax;
-	u64 rbx;
-	u64 rcx;
-	u64 rdx;
-	u64 cr2;
-	u64 rbp;
-	u64 rsi;
-	u64 rdi;
-	u64 r8;
-	u64 r9;
-	u64 r10;
-	u64 r11;
-	u64 r12;
-	u64 r13;
-	u64 r14;
-	u64 r15;
-	u64 rflags;
-};
-
 typedef void (*test_guest_func)(struct svm_test *);
 
 int run_svm_tests(int ac, char **av, struct svm_test *svm_tests);
@@ -55,58 +35,12 @@ bool default_finished(struct svm_test *test);
 int get_test_stage(struct svm_test *test);
 void set_test_stage(struct svm_test *test, int s);
 void inc_test_stage(struct svm_test *test);
-struct regs get_regs(void);
+struct svm_gprs *get_regs(void);
 int __svm_vmrun(u64 rip);
 void __svm_bare_vmrun(void);
 int svm_vmrun(void);
 void test_set_guest(test_guest_func func);
 
 extern struct vmcb *vmcb;
-
-
-#define SAVE_GPR_C                              \
-        "xchg %%rbx, regs+0x8\n\t"              \
-        "xchg %%rcx, regs+0x10\n\t"             \
-        "xchg %%rdx, regs+0x18\n\t"             \
-        "xchg %%rbp, regs+0x28\n\t"             \
-        "xchg %%rsi, regs+0x30\n\t"             \
-        "xchg %%rdi, regs+0x38\n\t"             \
-        "xchg %%r8, regs+0x40\n\t"              \
-        "xchg %%r9, regs+0x48\n\t"              \
-        "xchg %%r10, regs+0x50\n\t"             \
-        "xchg %%r11, regs+0x58\n\t"             \
-        "xchg %%r12, regs+0x60\n\t"             \
-        "xchg %%r13, regs+0x68\n\t"             \
-        "xchg %%r14, regs+0x70\n\t"             \
-        "xchg %%r15, regs+0x78\n\t"
-
-#define LOAD_GPR_C      SAVE_GPR_C
-
-#define ASM_PRE_VMRUN_CMD                       \
-                "vmload %%rax\n\t"              \
-                "mov regs+0x80, %%r15\n\t"      \
-                "mov %%r15, 0x170(%%rax)\n\t"   \
-                "mov regs, %%r15\n\t"           \
-                "mov %%r15, 0x1f8(%%rax)\n\t"   \
-                LOAD_GPR_C                      \
-
-#define ASM_POST_VMRUN_CMD                      \
-                SAVE_GPR_C                      \
-                "mov 0x170(%%rax), %%r15\n\t"   \
-                "mov %%r15, regs+0x80\n\t"      \
-                "mov 0x1f8(%%rax), %%r15\n\t"   \
-                "mov %%r15, regs\n\t"           \
-                "vmsave %%rax\n\t"              \
-
-
-
-#define SVM_BARE_VMRUN \
-	asm volatile ( \
-		ASM_PRE_VMRUN_CMD \
-                "vmrun %%rax\n\t"               \
-		ASM_POST_VMRUN_CMD \
-		: \
-		: "a" (virt_to_phys(vmcb)) \
-		: "memory", "r15") \
-
+extern struct svm_test svm_tests[];
 #endif
diff --git a/x86/svm_tests.c b/x86/svm_tests.c
index 712d24e2..70e41300 100644
--- a/x86/svm_tests.c
+++ b/x86/svm_tests.c
@@ -399,7 +399,7 @@ static bool msr_intercept_finished(struct svm_test *test)
 		 * RCX holds the MSR index.
 		 */
 		printf("%s 0x%lx #GP exception\n",
-		       exit_info_1 ? "WRMSR" : "RDMSR", get_regs().rcx);
+		       exit_info_1 ? "WRMSR" : "RDMSR", get_regs()->rcx);
 	}
 
 	/* Jump over RDMSR/WRMSR instruction */
@@ -415,9 +415,9 @@ static bool msr_intercept_finished(struct svm_test *test)
 	 */
 	if (exit_info_1)
 		test->scratch =
-			((get_regs().rdx << 32) | (vmcb->save.rax & 0xffffffff));
+			((get_regs()->rdx << 32) | (get_regs()->rax & 0xffffffff));
 	else
-		test->scratch = get_regs().rcx;
+		test->scratch = get_regs()->rcx;
 
 	return false;
 }
@@ -1842,7 +1842,7 @@ static volatile bool host_rflags_set_tf = false;
 static volatile bool host_rflags_set_rf = false;
 static u64 rip_detected;
 
-extern u64 *vmrun_rip;
+extern u64 vmrun_rip;
 
 static void host_rflags_db_handler(struct ex_regs *r)
 {
@@ -2878,6 +2878,8 @@ static void svm_lbrv_test0(void)
 
 static void svm_lbrv_test1(void)
 {
+	struct svm_gprs *regs = get_regs();
+
 	report(true, "Test that without LBRV enabled, guest LBR state does 'leak' to the host(1)");
 
 	vmcb->save.rip = (ulong)svm_lbrv_test_guest1;
@@ -2885,7 +2887,7 @@ static void svm_lbrv_test1(void)
 
 	wrmsr(MSR_IA32_DEBUGCTLMSR, DEBUGCTLMSR_LBR);
 	DO_BRANCH(host_branch1);
-	SVM_BARE_VMRUN;
+	SVM_VMRUN(vmcb, regs);
 	dbgctl = rdmsr(MSR_IA32_DEBUGCTLMSR);
 
 	if (vmcb->control.exit_code != SVM_EXIT_VMMCALL) {
@@ -2900,6 +2902,8 @@ static void svm_lbrv_test1(void)
 
 static void svm_lbrv_test2(void)
 {
+	struct svm_gprs *regs = get_regs();
+
 	report(true, "Test that without LBRV enabled, guest LBR state does 'leak' to the host(2)");
 
 	vmcb->save.rip = (ulong)svm_lbrv_test_guest2;
@@ -2908,7 +2912,7 @@ static void svm_lbrv_test2(void)
 	wrmsr(MSR_IA32_DEBUGCTLMSR, DEBUGCTLMSR_LBR);
 	DO_BRANCH(host_branch2);
 	wrmsr(MSR_IA32_DEBUGCTLMSR, 0);
-	SVM_BARE_VMRUN;
+	SVM_VMRUN(vmcb, regs);
 	dbgctl = rdmsr(MSR_IA32_DEBUGCTLMSR);
 	wrmsr(MSR_IA32_DEBUGCTLMSR, 0);
 
@@ -2924,6 +2928,8 @@ static void svm_lbrv_test2(void)
 
 static void svm_lbrv_nested_test1(void)
 {
+	struct svm_gprs *regs = get_regs();
+
 	if (!lbrv_supported()) {
 		report_skip("LBRV not supported in the guest");
 		return;
@@ -2936,7 +2942,7 @@ static void svm_lbrv_nested_test1(void)
 
 	wrmsr(MSR_IA32_DEBUGCTLMSR, DEBUGCTLMSR_LBR);
 	DO_BRANCH(host_branch3);
-	SVM_BARE_VMRUN;
+	SVM_VMRUN(vmcb, regs);
 	dbgctl = rdmsr(MSR_IA32_DEBUGCTLMSR);
 	wrmsr(MSR_IA32_DEBUGCTLMSR, 0);
 
@@ -2957,6 +2963,8 @@ static void svm_lbrv_nested_test1(void)
 
 static void svm_lbrv_nested_test2(void)
 {
+	struct svm_gprs *regs = get_regs();
+
 	if (!lbrv_supported()) {
 		report_skip("LBRV not supported in the guest");
 		return;
@@ -2972,7 +2980,7 @@ static void svm_lbrv_nested_test2(void)
 
 	wrmsr(MSR_IA32_DEBUGCTLMSR, DEBUGCTLMSR_LBR);
 	DO_BRANCH(host_branch4);
-	SVM_BARE_VMRUN;
+	SVM_VMRUN(vmcb, regs);
 	dbgctl = rdmsr(MSR_IA32_DEBUGCTLMSR);
 	wrmsr(MSR_IA32_DEBUGCTLMSR, 0);
 
-- 
2.34.3