Add vmentry failed handler to vmx framework to catch direct fail of
vmentry. When vmlaunch/vmresume directly fail to the next instruction,
a entry failed handler is used to handle this failure. Resume failure
from entry failed handler will cause entry double fail and directly
exit to L1.
Signed-off-by: Arthur Chunqi Li <yzt356@xxxxxxxxx>
---
lib/x86/vm.h | 3 +++
x86/vmx.c | 34 ++++++++++++++++++++--------------
x86/vmx.h | 15 +++++++++++++--
x86/vmx_tests.c | 31 +++++++++++++++++++++----------
4 files changed, 57 insertions(+), 26 deletions(-)
diff --git a/lib/x86/vm.h b/lib/x86/vm.h
index 6e0ce2b..c8565b5 100644
--- a/lib/x86/vm.h
+++ b/lib/x86/vm.h
@@ -19,7 +19,10 @@
#define X86_CR0_PE 0x00000001
#define X86_CR0_MP 0x00000002
#define X86_CR0_TS 0x00000008
+#define X86_CR0_ET 0x00000010
#define X86_CR0_WP 0x00010000
+#define X86_CR0_NW 0x20000000
+#define X86_CR0_CD 0x40000000
#define X86_CR0_PG 0x80000000
#define X86_CR4_VMXE 0x00000001
#define X86_CR4_TSD 0x00000004
diff --git a/x86/vmx.c b/x86/vmx.c
index 9db4ef4..6a2bf44 100644
--- a/x86/vmx.c
+++ b/x86/vmx.c
@@ -44,14 +44,6 @@ void report(const char *name, int result)
}
}
-static int make_vmcs_current(struct vmcs *vmcs)
-{
- bool ret;
-
- asm volatile ("vmptrld %1; setbe %0" : "=q" (ret) : "m" (vmcs) : "cc");
- return ret;
-}
-
/* entry_sysenter */
asm(
".align 4, 0x90\n\t"
@@ -631,6 +623,7 @@ static int exit_handler()
static int vmx_run()
{
u32 ret = 0, fail = 0;
+ bool entry_double_fail = false;
while (1) {
asm volatile (
@@ -657,28 +650,41 @@ static int vmx_run()
);
if (fail)
- ret = launched ? VMX_TEST_RESUME_ERR :
- VMX_TEST_LAUNCH_ERR;
+ if (entry_double_fail)
+ ret = launched ? VMX_TEST_RESUME_ERR :
+ VMX_TEST_LAUNCH_ERR;
+ else {
+ ret = current->entry_failed_handler(launched);
+ if (ret == VMX_TEST_RESUME) {
+ entry_double_fail = true;
+ host_rflags &= ~(X86_EFLAGS_ZF |
+ X86_EFLAGS_CF);
+ }
+ }
else {
launched = 1;
+ entry_double_fail = false;
ret = exit_handler();
}
if (ret != VMX_TEST_RESUME)
break;
+ ret = fail = 0;
}
launched = 0;
switch (ret) {
case VMX_TEST_VMEXIT:
return 0;
case VMX_TEST_LAUNCH_ERR:
- printf("%s : vmlaunch failed.\n", __func__);
+ printf("%s : vmlaunch failed, entry_double_fail=%d.\n",
+ __func__, entry_double_fail);
if ((!(host_rflags & X86_EFLAGS_CF) && !(host_rflags & X86_EFLAGS_ZF))
|| ((host_rflags & X86_EFLAGS_CF) && (host_rflags & X86_EFLAGS_ZF)))
printf("\tvmlaunch set wrong flags\n");
report("test vmlaunch", 0);
break;
case VMX_TEST_RESUME_ERR:
- printf("%s : vmresume failed.\n", __func__);
+ printf("%s : vmresume failed, entry_double_fail=%d.\n",
+ __func__, entry_double_fail);
if ((!(host_rflags & X86_EFLAGS_CF) && !(host_rflags & X86_EFLAGS_ZF))
|| ((host_rflags & X86_EFLAGS_CF) && (host_rflags & X86_EFLAGS_ZF)))
printf("\tvmresume set wrong flags\n");
@@ -700,12 +706,12 @@ static int test_run(struct vmx_test *test)
return 1;
}
init_vmcs(&(test->vmcs));
+ current = test;
/* Directly call test->init is ok here, init_vmcs has done
vmcs init, vmclear and vmptrld*/
if (test->init)
- test->init(test->vmcs);
+ test->init();
test->exits = 0;
- current = test;
regs = test->guest_regs;
vmcs_write(GUEST_RFLAGS, regs.rflags | 0x2);
launched = 0;
diff --git a/x86/vmx.h b/x86/vmx.h
index dc1ebdf..469b4dc 100644
--- a/x86/vmx.h
+++ b/x86/vmx.h
@@ -4,7 +4,8 @@
#include "libcflat.h"
struct vmcs {
- u32 revision_id; /* vmcs revision identifier */
+ u32 revision_id:31, /* vmcs revision identifier */
+ shadow:1; /* shadow-VMCS indicator */
u32 abort; /* VMX-abort indicator */
/* VMCS data */
char data[0];
@@ -32,10 +33,11 @@ struct regs {
struct vmx_test {
const char *name;
- void (*init)(struct vmcs *vmcs);
+ void (*init)();
void (*guest_main)();
int (*exit_handler)();
void (*syscall_handler)(u64 syscall_no);
+ int (*entry_failed_handler)();
struct regs guest_regs;
struct vmcs *vmcs;
int exits;
@@ -378,6 +380,7 @@ enum Ctrl1 {
CPU_URG = 1ul << 7,
CPU_WBINVD = 1ul << 6,
CPU_RDRAND = 1ul << 11,
+ CPU_SHADOW = 1ul << 14,
};
#define SAVE_GPR \
@@ -512,6 +515,14 @@ extern union vmx_ctrl_exit ctrl_exit_rev;
extern union vmx_ctrl_ent ctrl_enter_rev;
extern union vmx_ept_vpid ept_vpid;
+static int make_vmcs_current(struct vmcs *vmcs)
+{
+ bool ret;
+
+ asm volatile ("vmptrld %1; setbe %0" : "=q" (ret) : "m" (vmcs) : "cc");
+ return ret;
+}
+
static inline int vmcs_clear(struct vmcs *vmcs)
{
bool ret;
diff --git a/x86/vmx_tests.c b/x86/vmx_tests.c
index 0759e10..e95e6b8 100644
--- a/x86/vmx_tests.c
+++ b/x86/vmx_tests.c
@@ -73,6 +73,12 @@ void basic_syscall_handler(u64 syscall_no)
{
}
+int basic_entry_failed_handler()
+{
+ return launched ? VMX_TEST_RESUME_ERR :
+ VMX_TEST_LAUNCH_ERR;
+}
+
void vmenter_main()
{
u64 rax;
@@ -1111,22 +1117,27 @@ static int ept_exit_handler()
basic_* just implement some basic functions */
struct vmx_test vmx_tests[] = {
{ "null", basic_init, basic_guest_main, basic_exit_handler,
- basic_syscall_handler, {0} },
+ basic_syscall_handler, basic_entry_failed_handler, {0} },
{ "vmenter", basic_init, vmenter_main, vmenter_exit_handler,
- basic_syscall_handler, {0} },
+ basic_syscall_handler, basic_entry_failed_handler, {0} },
{ "preemption timer", preemption_timer_init, preemption_timer_main,
- preemption_timer_exit_handler, basic_syscall_handler, {0} },
+ preemption_timer_exit_handler, basic_syscall_handler,
+ basic_entry_failed_handler, {0} },
{ "control field PAT", test_ctrl_pat_init, test_ctrl_pat_main,
- test_ctrl_pat_exit_handler, basic_syscall_handler, {0} },
+ test_ctrl_pat_exit_handler, basic_syscall_handler,
+ basic_entry_failed_handler, {0} },
{ "control field EFER", test_ctrl_efer_init, test_ctrl_efer_main,
- test_ctrl_efer_exit_handler, basic_syscall_handler, {0} },
+ test_ctrl_efer_exit_handler, basic_syscall_handler,
+ basic_entry_failed_handler, {0} },
{ "CR shadowing", basic_init, cr_shadowing_main,
- cr_shadowing_exit_handler, basic_syscall_handler, {0} },
+ cr_shadowing_exit_handler, basic_syscall_handler,
+ basic_entry_failed_handler, {0} },
{ "I/O bitmap", iobmp_init, iobmp_main, iobmp_exit_handler,
- basic_syscall_handler, {0} },
+ basic_syscall_handler, basic_entry_failed_handler, {0} },
{ "instruction intercept", insn_intercept_init, insn_intercept_main,
- insn_intercept_exit_handler, basic_syscall_handler, {0} },
+ insn_intercept_exit_handler, basic_syscall_handler,
+ basic_entry_failed_handler, {0} },
{ "EPT framework", ept_init, ept_main, ept_exit_handler,
- basic_syscall_handler, {0} },
- { NULL, NULL, NULL, NULL, NULL, {0} },
+ basic_syscall_handler, basic_entry_failed_handler, {0} },
+ { NULL, NULL, NULL, NULL, NULL, NULL, {0} },
};
--
1.7.9.5
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