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-rw-r--r--arch/x86/include/asm/kvm_host.h22
-rw-r--r--arch/x86/include/asm/vmx.h2
-rw-r--r--arch/x86/kvm/kvm_svm.h6
-rw-r--r--arch/x86/kvm/svm.c116
-rw-r--r--arch/x86/kvm/vmx.c114
-rw-r--r--arch/x86/kvm/x86.c29
6 files changed, 193 insertions, 96 deletions
diff --git a/arch/x86/include/asm/kvm_host.h b/arch/x86/include/asm/kvm_host.h
index c430cd580ee2..0a4dab25a919 100644
--- a/arch/x86/include/asm/kvm_host.h
+++ b/arch/x86/include/asm/kvm_host.h
@@ -135,6 +135,19 @@ enum {
#define KVM_NR_MEM_OBJS 40
+#define KVM_NR_DB_REGS 4
+
+#define DR6_BD (1 << 13)
+#define DR6_BS (1 << 14)
+#define DR6_FIXED_1 0xffff0ff0
+#define DR6_VOLATILE 0x0000e00f
+
+#define DR7_BP_EN_MASK 0x000000ff
+#define DR7_GE (1 << 9)
+#define DR7_GD (1 << 13)
+#define DR7_FIXED_1 0x00000400
+#define DR7_VOLATILE 0xffff23ff
+
/*
* We don't want allocation failures within the mmu code, so we preallocate
* enough memory for a single page fault in a cache.
@@ -334,6 +347,15 @@ struct kvm_vcpu_arch {
struct mtrr_state_type mtrr_state;
u32 pat;
+
+ int switch_db_regs;
+ unsigned long host_db[KVM_NR_DB_REGS];
+ unsigned long host_dr6;
+ unsigned long host_dr7;
+ unsigned long db[KVM_NR_DB_REGS];
+ unsigned long dr6;
+ unsigned long dr7;
+ unsigned long eff_db[KVM_NR_DB_REGS];
};
struct kvm_mem_alias {
diff --git a/arch/x86/include/asm/vmx.h b/arch/x86/include/asm/vmx.h
index 32159f034efc..498f944010b9 100644
--- a/arch/x86/include/asm/vmx.h
+++ b/arch/x86/include/asm/vmx.h
@@ -312,7 +312,7 @@ enum vmcs_field {
#define DEBUG_REG_ACCESS_TYPE 0x10 /* 4, direction of access */
#define TYPE_MOV_TO_DR (0 << 4)
#define TYPE_MOV_FROM_DR (1 << 4)
-#define DEBUG_REG_ACCESS_REG 0xf00 /* 11:8, general purpose reg. */
+#define DEBUG_REG_ACCESS_REG(eq) (((eq) >> 8) & 0xf) /* 11:8, general purpose reg. */
/* segment AR */
diff --git a/arch/x86/kvm/kvm_svm.h b/arch/x86/kvm/kvm_svm.h
index 91673413d8f7..ed66e4c078dc 100644
--- a/arch/x86/kvm/kvm_svm.h
+++ b/arch/x86/kvm/kvm_svm.h
@@ -18,7 +18,6 @@ static const u32 host_save_user_msrs[] = {
};
#define NR_HOST_SAVE_USER_MSRS ARRAY_SIZE(host_save_user_msrs)
-#define NUM_DB_REGS 4
struct kvm_vcpu;
@@ -29,16 +28,11 @@ struct vcpu_svm {
struct svm_cpu_data *svm_data;
uint64_t asid_generation;
- unsigned long db_regs[NUM_DB_REGS];
-
u64 next_rip;
u64 host_user_msrs[NR_HOST_SAVE_USER_MSRS];
u64 host_gs_base;
unsigned long host_cr2;
- unsigned long host_db_regs[NUM_DB_REGS];
- unsigned long host_dr6;
- unsigned long host_dr7;
u32 *msrpm;
struct vmcb *hsave;
diff --git a/arch/x86/kvm/svm.c b/arch/x86/kvm/svm.c
index 88d9062f4545..815f50e425ac 100644
--- a/arch/x86/kvm/svm.c
+++ b/arch/x86/kvm/svm.c
@@ -38,9 +38,6 @@ MODULE_LICENSE("GPL");
#define IOPM_ALLOC_ORDER 2
#define MSRPM_ALLOC_ORDER 1
-#define DR7_GD_MASK (1 << 13)
-#define DR6_BD_MASK (1 << 13)
-
#define SEG_TYPE_LDT 2
#define SEG_TYPE_BUSY_TSS16 3
@@ -181,32 +178,6 @@ static inline void kvm_write_cr2(unsigned long val)
asm volatile ("mov %0, %%cr2" :: "r" (val));
}
-static inline unsigned long read_dr6(void)
-{
- unsigned long dr6;
-
- asm volatile ("mov %%dr6, %0" : "=r" (dr6));
- return dr6;
-}
-
-static inline void write_dr6(unsigned long val)
-{
- asm volatile ("mov %0, %%dr6" :: "r" (val));
-}
-
-static inline unsigned long read_dr7(void)
-{
- unsigned long dr7;
-
- asm volatile ("mov %%dr7, %0" : "=r" (dr7));
- return dr7;
-}
-
-static inline void write_dr7(unsigned long val)
-{
- asm volatile ("mov %0, %%dr7" :: "r" (val));
-}
-
static inline void force_new_asid(struct kvm_vcpu *vcpu)
{
to_svm(vcpu)->asid_generation--;
@@ -695,7 +666,6 @@ static struct kvm_vcpu *svm_create_vcpu(struct kvm *kvm, unsigned int id)
clear_page(svm->vmcb);
svm->vmcb_pa = page_to_pfn(page) << PAGE_SHIFT;
svm->asid_generation = 0;
- memset(svm->db_regs, 0, sizeof(svm->db_regs));
init_vmcb(svm);
fx_init(&svm->vcpu);
@@ -1035,7 +1005,29 @@ static void new_asid(struct vcpu_svm *svm, struct svm_cpu_data *svm_data)
static unsigned long svm_get_dr(struct kvm_vcpu *vcpu, int dr)
{
- unsigned long val = to_svm(vcpu)->db_regs[dr];
+ struct vcpu_svm *svm = to_svm(vcpu);
+ unsigned long val;
+
+ switch (dr) {
+ case 0 ... 3:
+ val = vcpu->arch.db[dr];
+ break;
+ case 6:
+ if (vcpu->guest_debug & KVM_GUESTDBG_USE_HW_BP)
+ val = vcpu->arch.dr6;
+ else
+ val = svm->vmcb->save.dr6;
+ break;
+ case 7:
+ if (vcpu->guest_debug & KVM_GUESTDBG_USE_HW_BP)
+ val = vcpu->arch.dr7;
+ else
+ val = svm->vmcb->save.dr7;
+ break;
+ default:
+ val = 0;
+ }
+
KVMTRACE_2D(DR_READ, vcpu, (u32)dr, (u32)val, handler);
return val;
}
@@ -1045,33 +1037,40 @@ static void svm_set_dr(struct kvm_vcpu *vcpu, int dr, unsigned long value,
{
struct vcpu_svm *svm = to_svm(vcpu);
- *exception = 0;
+ KVMTRACE_2D(DR_WRITE, vcpu, (u32)dr, (u32)value, handler);
- if (svm->vmcb->save.dr7 & DR7_GD_MASK) {
- svm->vmcb->save.dr7 &= ~DR7_GD_MASK;
- svm->vmcb->save.dr6 |= DR6_BD_MASK;
- *exception = DB_VECTOR;
- return;
- }
+ *exception = 0;
switch (dr) {
case 0 ... 3:
- svm->db_regs[dr] = value;
+ vcpu->arch.db[dr] = value;
+ if (!(vcpu->guest_debug & KVM_GUESTDBG_USE_HW_BP))
+ vcpu->arch.eff_db[dr] = value;
return;
case 4 ... 5:
- if (vcpu->arch.cr4 & X86_CR4_DE) {
+ if (vcpu->arch.cr4 & X86_CR4_DE)
*exception = UD_VECTOR;
+ return;
+ case 6:
+ if (value & 0xffffffff00000000ULL) {
+ *exception = GP_VECTOR;
return;
}
- case 7: {
- if (value & ~((1ULL << 32) - 1)) {
+ vcpu->arch.dr6 = (value & DR6_VOLATILE) | DR6_FIXED_1;
+ return;
+ case 7:
+ if (value & 0xffffffff00000000ULL) {
*exception = GP_VECTOR;
return;
}
- svm->vmcb->save.dr7 = value;
+ vcpu->arch.dr7 = (value & DR7_VOLATILE) | DR7_FIXED_1;
+ if (!(vcpu->guest_debug & KVM_GUESTDBG_USE_HW_BP)) {
+ svm->vmcb->save.dr7 = vcpu->arch.dr7;
+ vcpu->arch.switch_db_regs = (value & DR7_BP_EN_MASK);
+ }
return;
- }
default:
+ /* FIXME: Possible case? */
printk(KERN_DEBUG "%s: unexpected dr %u\n",
__func__, dr);
*exception = UD_VECTOR;
@@ -2365,22 +2364,6 @@ static int svm_set_tss_addr(struct kvm *kvm, unsigned int addr)
return 0;
}
-static void save_db_regs(unsigned long *db_regs)
-{
- asm volatile ("mov %%dr0, %0" : "=r"(db_regs[0]));
- asm volatile ("mov %%dr1, %0" : "=r"(db_regs[1]));
- asm volatile ("mov %%dr2, %0" : "=r"(db_regs[2]));
- asm volatile ("mov %%dr3, %0" : "=r"(db_regs[3]));
-}
-
-static void load_db_regs(unsigned long *db_regs)
-{
- asm volatile ("mov %0, %%dr0" : : "r"(db_regs[0]));
- asm volatile ("mov %0, %%dr1" : : "r"(db_regs[1]));
- asm volatile ("mov %0, %%dr2" : : "r"(db_regs[2]));
- asm volatile ("mov %0, %%dr3" : : "r"(db_regs[3]));
-}
-
static void svm_flush_tlb(struct kvm_vcpu *vcpu)
{
force_new_asid(vcpu);
@@ -2439,20 +2422,12 @@ static void svm_vcpu_run(struct kvm_vcpu *vcpu, struct kvm_run *kvm_run)
gs_selector = kvm_read_gs();
ldt_selector = kvm_read_ldt();
svm->host_cr2 = kvm_read_cr2();
- svm->host_dr6 = read_dr6();
- svm->host_dr7 = read_dr7();
if (!is_nested(svm))
svm->vmcb->save.cr2 = vcpu->arch.cr2;
/* required for live migration with NPT */
if (npt_enabled)
svm->vmcb->save.cr3 = vcpu->arch.cr3;
- if (svm->vmcb->save.dr7 & 0xff) {
- write_dr7(0);
- save_db_regs(svm->host_db_regs);
- load_db_regs(svm->db_regs);
- }
-
clgi();
local_irq_enable();
@@ -2528,16 +2503,11 @@ static void svm_vcpu_run(struct kvm_vcpu *vcpu, struct kvm_run *kvm_run)
#endif
);
- if ((svm->vmcb->save.dr7 & 0xff))
- load_db_regs(svm->host_db_regs);
-
vcpu->arch.cr2 = svm->vmcb->save.cr2;
vcpu->arch.regs[VCPU_REGS_RAX] = svm->vmcb->save.rax;
vcpu->arch.regs[VCPU_REGS_RSP] = svm->vmcb->save.rsp;
vcpu->arch.regs[VCPU_REGS_RIP] = svm->vmcb->save.rip;
- write_dr6(svm->host_dr6);
- write_dr7(svm->host_dr7);
kvm_write_cr2(svm->host_cr2);
kvm_load_fs(fs_selector);
diff --git a/arch/x86/kvm/vmx.c b/arch/x86/kvm/vmx.c
index c776868ffe41..0989776ee7b0 100644
--- a/arch/x86/kvm/vmx.c
+++ b/arch/x86/kvm/vmx.c
@@ -2311,7 +2311,6 @@ static int vmx_vcpu_reset(struct kvm_vcpu *vcpu)
kvm_rip_write(vcpu, 0);
kvm_register_write(vcpu, VCPU_REGS_RSP, 0);
- /* todo: dr0 = dr1 = dr2 = dr3 = 0; dr6 = 0xffff0ff0 */
vmcs_writel(GUEST_DR7, 0x400);
vmcs_writel(GUEST_GDTR_BASE, 0);
@@ -2577,7 +2576,7 @@ static int handle_exception(struct kvm_vcpu *vcpu, struct kvm_run *kvm_run)
{
struct vcpu_vmx *vmx = to_vmx(vcpu);
u32 intr_info, ex_no, error_code;
- unsigned long cr2, rip;
+ unsigned long cr2, rip, dr6;
u32 vect_info;
enum emulation_result er;
@@ -2637,14 +2636,28 @@ static int handle_exception(struct kvm_vcpu *vcpu, struct kvm_run *kvm_run)
}
ex_no = intr_info & INTR_INFO_VECTOR_MASK;
- if (ex_no == DB_VECTOR || ex_no == BP_VECTOR) {
+ switch (ex_no) {
+ case DB_VECTOR:
+ dr6 = vmcs_readl(EXIT_QUALIFICATION);
+ if (!(vcpu->guest_debug &
+ (KVM_GUESTDBG_SINGLESTEP | KVM_GUESTDBG_USE_HW_BP))) {
+ vcpu->arch.dr6 = dr6 | DR6_FIXED_1;
+ kvm_queue_exception(vcpu, DB_VECTOR);
+ return 1;
+ }
+ kvm_run->debug.arch.dr6 = dr6 | DR6_FIXED_1;
+ kvm_run->debug.arch.dr7 = vmcs_readl(GUEST_DR7);
+ /* fall through */
+ case BP_VECTOR:
kvm_run->exit_reason = KVM_EXIT_DEBUG;
kvm_run->debug.arch.pc = vmcs_readl(GUEST_CS_BASE) + rip;
kvm_run->debug.arch.exception = ex_no;
- } else {
+ break;
+ default:
kvm_run->exit_reason = KVM_EXIT_EXCEPTION;
kvm_run->ex.exception = ex_no;
kvm_run->ex.error_code = error_code;
+ break;
}
return 0;
}
@@ -2784,21 +2797,44 @@ static int handle_dr(struct kvm_vcpu *vcpu, struct kvm_run *kvm_run)
unsigned long val;
int dr, reg;
- /*
- * FIXME: this code assumes the host is debugging the guest.
- * need to deal with guest debugging itself too.
- */
+ dr = vmcs_readl(GUEST_DR7);
+ if (dr & DR7_GD) {
+ /*
+ * As the vm-exit takes precedence over the debug trap, we
+ * need to emulate the latter, either for the host or the
+ * guest debugging itself.
+ */
+ if (vcpu->guest_debug & KVM_GUESTDBG_USE_HW_BP) {
+ kvm_run->debug.arch.dr6 = vcpu->arch.dr6;
+ kvm_run->debug.arch.dr7 = dr;
+ kvm_run->debug.arch.pc =
+ vmcs_readl(GUEST_CS_BASE) +
+ vmcs_readl(GUEST_RIP);
+ kvm_run->debug.arch.exception = DB_VECTOR;
+ kvm_run->exit_reason = KVM_EXIT_DEBUG;
+ return 0;
+ } else {
+ vcpu->arch.dr7 &= ~DR7_GD;
+ vcpu->arch.dr6 |= DR6_BD;
+ vmcs_writel(GUEST_DR7, vcpu->arch.dr7);
+ kvm_queue_exception(vcpu, DB_VECTOR);
+ return 1;
+ }
+ }
+
exit_qualification = vmcs_readl(EXIT_QUALIFICATION);
- dr = exit_qualification & 7;
- reg = (exit_qualification >> 8) & 15;
- if (exit_qualification & 16) {
- /* mov from dr */
+ dr = exit_qualification & DEBUG_REG_ACCESS_NUM;
+ reg = DEBUG_REG_ACCESS_REG(exit_qualification);
+ if (exit_qualification & TYPE_MOV_FROM_DR) {
switch (dr) {
+ case 0 ... 3:
+ val = vcpu->arch.db[dr];
+ break;
case 6:
- val = 0xffff0ff0;
+ val = vcpu->arch.dr6;
break;
case 7:
- val = 0x400;
+ val = vcpu->arch.dr7;
break;
default:
val = 0;
@@ -2806,7 +2842,38 @@ static int handle_dr(struct kvm_vcpu *vcpu, struct kvm_run *kvm_run)
kvm_register_write(vcpu, reg, val);
KVMTRACE_2D(DR_READ, vcpu, (u32)dr, (u32)val, handler);
} else {
- /* mov to dr */
+ val = vcpu->arch.regs[reg];
+ switch (dr) {
+ case 0 ... 3:
+ vcpu->arch.db[dr] = val;
+ if (!(vcpu->guest_debug & KVM_GUESTDBG_USE_HW_BP))
+ vcpu->arch.eff_db[dr] = val;
+ break;
+ case 4 ... 5:
+ if (vcpu->arch.cr4 & X86_CR4_DE)
+ kvm_queue_exception(vcpu, UD_VECTOR);
+ break;
+ case 6:
+ if (val & 0xffffffff00000000ULL) {
+ kvm_queue_exception(vcpu, GP_VECTOR);
+ break;
+ }
+ vcpu->arch.dr6 = (val & DR6_VOLATILE) | DR6_FIXED_1;
+ break;
+ case 7:
+ if (val & 0xffffffff00000000ULL) {
+ kvm_queue_exception(vcpu, GP_VECTOR);
+ break;
+ }
+ vcpu->arch.dr7 = (val & DR7_VOLATILE) | DR7_FIXED_1;
+ if (!(vcpu->guest_debug & KVM_GUESTDBG_USE_HW_BP)) {
+ vmcs_writel(GUEST_DR7, vcpu->arch.dr7);
+ vcpu->arch.switch_db_regs =
+ (val & DR7_BP_EN_MASK);
+ }
+ break;
+ }
+ KVMTRACE_2D(DR_WRITE, vcpu, (u32)dr, (u32)val, handler);
}
skip_emulated_instruction(vcpu);
return 1;
@@ -2957,7 +3024,18 @@ static int handle_task_switch(struct kvm_vcpu *vcpu, struct kvm_run *kvm_run)
}
tss_selector = exit_qualification;
- return kvm_task_switch(vcpu, tss_selector, reason);
+ if (!kvm_task_switch(vcpu, tss_selector, reason))
+ return 0;
+
+ /* clear all local breakpoint enable flags */
+ vmcs_writel(GUEST_DR7, vmcs_readl(GUEST_DR7) & ~55);
+
+ /*
+ * TODO: What about debug traps on tss switch?
+ * Are we supposed to inject them and update dr6?
+ */
+
+ return 1;
}
static int handle_ept_violation(struct kvm_vcpu *vcpu, struct kvm_run *kvm_run)
@@ -3342,6 +3420,8 @@ static void vmx_vcpu_run(struct kvm_vcpu *vcpu, struct kvm_run *kvm_run)
*/
vmcs_writel(HOST_CR0, read_cr0());
+ set_debugreg(vcpu->arch.dr6, 6);
+
asm(
/* Store host registers */
"push %%"R"dx; push %%"R"bp;"
@@ -3436,6 +3516,8 @@ static void vmx_vcpu_run(struct kvm_vcpu *vcpu, struct kvm_run *kvm_run)
vcpu->arch.regs_avail = ~((1 << VCPU_REGS_RIP) | (1 << VCPU_REGS_RSP));
vcpu->arch.regs_dirty = 0;
+ get_debugreg(vcpu->arch.dr6, 6);
+
vmx->idt_vectoring_info = vmcs_read32(IDT_VECTORING_INFO_FIELD);
if (vmx->rmode.irq.pending)
fixup_rmode_irq(vmx);
diff --git a/arch/x86/kvm/x86.c b/arch/x86/kvm/x86.c
index e990d164b56d..300bc4d42abc 100644
--- a/arch/x86/kvm/x86.c
+++ b/arch/x86/kvm/x86.c
@@ -3025,10 +3025,34 @@ static int vcpu_enter_guest(struct kvm_vcpu *vcpu, struct kvm_run *kvm_run)
kvm_guest_enter();
+ get_debugreg(vcpu->arch.host_dr6, 6);
+ get_debugreg(vcpu->arch.host_dr7, 7);
+ if (unlikely(vcpu->arch.switch_db_regs)) {
+ get_debugreg(vcpu->arch.host_db[0], 0);
+ get_debugreg(vcpu->arch.host_db[1], 1);
+ get_debugreg(vcpu->arch.host_db[2], 2);
+ get_debugreg(vcpu->arch.host_db[3], 3);
+
+ set_debugreg(0, 7);
+ set_debugreg(vcpu->arch.eff_db[0], 0);
+ set_debugreg(vcpu->arch.eff_db[1], 1);
+ set_debugreg(vcpu->arch.eff_db[2], 2);
+ set_debugreg(vcpu->arch.eff_db[3], 3);
+ }
KVMTRACE_0D(VMENTRY, vcpu, entryexit);
kvm_x86_ops->run(vcpu, kvm_run);
+ if (unlikely(vcpu->arch.switch_db_regs)) {
+ set_debugreg(0, 7);
+ set_debugreg(vcpu->arch.host_db[0], 0);
+ set_debugreg(vcpu->arch.host_db[1], 1);
+ set_debugreg(vcpu->arch.host_db[2], 2);
+ set_debugreg(vcpu->arch.host_db[3], 3);
+ }
+ set_debugreg(vcpu->arch.host_dr6, 6);
+ set_debugreg(vcpu->arch.host_dr7, 7);
+
vcpu->guest_mode = 0;
local_irq_enable();
@@ -4035,6 +4059,11 @@ int kvm_arch_vcpu_reset(struct kvm_vcpu *vcpu)
vcpu->arch.nmi_pending = false;
vcpu->arch.nmi_injected = false;
+ vcpu->arch.switch_db_regs = 0;
+ memset(vcpu->arch.db, 0, sizeof(vcpu->arch.db));
+ vcpu->arch.dr6 = DR6_FIXED_1;
+ vcpu->arch.dr7 = DR7_FIXED_1;
+
return kvm_x86_ops->vcpu_reset(vcpu);
}
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