[PATCH kvm-unit-tests 3/4] x86: check register values after reset

[Nadav Amit]

Checking the reset values of dr0, cr2 and sysenter_eip after reset.  Since INIT
does not initialize certain registers, we keep for each state whether it is
INIT or not. It is also required for the next patch.

Signed-off-by: Nadav Amit <na...@cs.technion.ac.il>
---
 x86/init.c | 55 +++++++++++++++++++++++++++++++++++++++++++++++++++++++
 1 file changed, 55 insertions(+)

diff --git a/x86/init.c b/x86/init.c
index 717bd12..3694d67 100644
--- a/x86/init.c
+++ b/x86/init.c
@@ -1,6 +1,8 @@
 #include "libcflat.h"
 #include "apic.h"
 #include "io.h"
+#include "processor.h"
+#include "msr.h"
 
 #define CHECK_HARD_RESET       0
 
@@ -36,9 +38,51 @@ static inline void rtc_out(u8 reg, u8 val)
 
 extern char resume_start, resume_end;
 
+struct expected_state {
+       bool init;
+};
+
+static struct expected_state expected[] = {
+       {.init = false},
+       {.init = false},
+       {.init = false},
+       {.init = false},
+       {.init = true},
+};
+
 #define state (*(volatile int *)0x2000)
 #define bad (*(volatile int *)0x2004)
 #define resumed (*(volatile int *)0x2008)
+#define dr0 (*(volatile int*)0x200c)
+#define cr2 (*(volatile int*)0x2010)
+#define sysenter_eip (*(volatile int*)0x2014)
+
+static void set_test_regs(void)
+{
+       write_dr0(1);
+       write_cr2(1);
+       wrmsr(MSR_IA32_SYSENTER_EIP, 1);
+}
+
+static bool check_test_regs(bool init)
+{
+       bool error = false;
+
+       if (dr0 != 0) {
+               printf("error: dr0 was not initialized: %x\n", dr0);
+               error = true;
+       }
+       if (cr2 != 0) {
+               printf("error: cr2 was not initialized\n", cr2);
+               error = true;
+       }
+       if (init && sysenter_eip != 1) {
+               printf("wrong sysenter_eip msr: %x\n", sysenter_eip);
+               error = true;
+       }
+
+       return error;
+}
 
 int main(int argc, char **argv)
 {
@@ -63,6 +107,9 @@ int main(int argc, char **argv)
                        bad |= 2;
                }
 
+               if (check_test_regs(expected[state-1].init))
+                       bad |= 4;
+
 #if CHECK_HARD_RESET
                /*
                 * Port 92 bit 0 is cleared on system reset.  On a soft reset it
@@ -76,6 +123,7 @@ int main(int argc, char **argv)
 #endif
        }
 
+       set_test_regs();
        resumed = 0;
 
        switch (state++) {
@@ -122,6 +170,13 @@ asm (
        ".code16\n"
        "resume_start:\n"
        "incb %cs:0x2008\n"             // resumed++;
+       "mov %dr0, %ecx\n"
+       "mov %ecx, %cs:0x200c\n"        // dr0
+       "mov %cr2, %ecx\n"
+       "mov %ecx, %cs:0x2010\n"        // cr2
+       "mov $0x176, %ecx\n"
+       "rdmsr\n"
+       "mov %eax, %cs:0x2014\n"        // sysenter_eip
        "mov $0x0f, %al\n"              // rtc_out(0x0f, 0x00);
        "out %al, $0x70\n"
        "mov $0x00, %al\n"
-- 
1.9.1

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