This introduces a level of indirection for the debug registers. Instead
of using the sys_regs[] directly we store registers in a structure in
the vcpu. As we are no longer tied to the layout of the sys_regs[] we
can make the copies size appropriate for control and value registers.
This also entails updating the sys_regs code to access this new
structure. Instead of passing a register index we now pass an offset
into the kvm_guest_debug_arch structure.
We also need to ensure the GET/SET_ONE_REG ioctl operations store the
registers in their correct location.
Signed-off-by: Alex Bennée <[email protected]>
diff --git a/arch/arm/kvm/arm.c b/arch/arm/kvm/arm.c
index 9b3ed6d..0d17c7b 100644
--- a/arch/arm/kvm/arm.c
+++ b/arch/arm/kvm/arm.c
@@ -279,6 +279,9 @@ int kvm_arch_vcpu_init(struct kvm_vcpu *vcpu)
/* Set up the timer */
kvm_timer_vcpu_init(vcpu);
+ /* Set the debug registers to be the guests */
+ vcpu->arch.debug_ptr = &vcpu->arch.vcpu_debug_state;
+
return 0;
}
diff --git a/arch/arm64/include/asm/kvm_asm.h b/arch/arm64/include/asm/kvm_asm.h
index d6b507e..e997404 100644
--- a/arch/arm64/include/asm/kvm_asm.h
+++ b/arch/arm64/include/asm/kvm_asm.h
@@ -46,24 +46,16 @@
#define CNTKCTL_EL1 20 /* Timer Control Register (EL1) */
#define PAR_EL1 21 /* Physical Address Register */
#define MDSCR_EL1 22 /* Monitor Debug System Control Register */
-#define DBGBCR0_EL1 23 /* Debug Breakpoint Control Registers (0-15) */
-#define DBGBCR15_EL1 38
-#define DBGBVR0_EL1 39 /* Debug Breakpoint Value Registers (0-15) */
-#define DBGBVR15_EL1 54
-#define DBGWCR0_EL1 55 /* Debug Watchpoint Control Registers (0-15) */
-#define DBGWCR15_EL1 70
-#define DBGWVR0_EL1 71 /* Debug Watchpoint Value Registers (0-15) */
-#define DBGWVR15_EL1 86
-#define MDCCINT_EL1 87 /* Monitor Debug Comms Channel Interrupt Enable Reg */
+#define MDCCINT_EL1 23 /* Monitor Debug Comms Channel Interrupt Enable Reg */
/* 32bit specific registers. Keep them at the end of the range */
-#define DACR32_EL2 88 /* Domain Access Control Register */
-#define IFSR32_EL2 89 /* Instruction Fault Status Register */
-#define FPEXC32_EL2 90 /* Floating-Point Exception Control Register */
-#define DBGVCR32_EL2 91 /* Debug Vector Catch Register */
-#define TEECR32_EL1 92 /* ThumbEE Configuration Register */
-#define TEEHBR32_EL1 93 /* ThumbEE Handler Base Register */
-#define NR_SYS_REGS 94
+#define DACR32_EL2 24 /* Domain Access Control Register */
+#define IFSR32_EL2 25 /* Instruction Fault Status Register */
+#define FPEXC32_EL2 26 /* Floating-Point Exception Control Register */
+#define DBGVCR32_EL2 27 /* Debug Vector Catch Register */
+#define TEECR32_EL1 28 /* ThumbEE Configuration Register */
+#define TEEHBR32_EL1 29 /* ThumbEE Handler Base Register */
+#define NR_SYS_REGS 30
/* 32bit mapping */
#define c0_MPIDR (MPIDR_EL1 * 2) /* MultiProcessor ID Register */
diff --git a/arch/arm64/include/asm/kvm_host.h b/arch/arm64/include/asm/kvm_host.h
index 3ab31d7..ad792cb 100644
--- a/arch/arm64/include/asm/kvm_host.h
+++ b/arch/arm64/include/asm/kvm_host.h
@@ -108,11 +108,21 @@ struct kvm_vcpu_arch {
/* Exception Information */
struct kvm_vcpu_fault_info fault;
- /* Debug state */
+ /* Guest debug state */
u64 debug_flags;
+ /*
+ * For debugging the guest we need to keep a set of debug
+ * registers which can override the guests own debug state
+ * while being used. These are set via the KVM_SET_GUEST_DEBUG
+ * ioctl.
+ */
+ struct kvm_guest_debug_arch *debug_ptr;
+ struct kvm_guest_debug_arch vcpu_debug_state;
+
/* Pointer to host CPU context */
kvm_cpu_context_t *host_cpu_context;
+ struct kvm_guest_debug_arch host_debug_state;
/* VGIC state */
struct vgic_cpu vgic_cpu;
diff --git a/arch/arm64/kernel/asm-offsets.c b/arch/arm64/kernel/asm-offsets.c
index dfb25a2..1a8e97c 100644
--- a/arch/arm64/kernel/asm-offsets.c
+++ b/arch/arm64/kernel/asm-offsets.c
@@ -116,10 +116,16 @@ int main(void)
DEFINE(VCPU_FAR_EL2, offsetof(struct kvm_vcpu, arch.fault.far_el2));
DEFINE(VCPU_HPFAR_EL2, offsetof(struct kvm_vcpu, arch.fault.hpfar_el2));
DEFINE(VCPU_DEBUG_FLAGS, offsetof(struct kvm_vcpu, arch.debug_flags));
+ DEFINE(VCPU_DEBUG_PTR, offsetof(struct kvm_vcpu, arch.debug_ptr));
+ DEFINE(DEBUG_BCR, offsetof(struct kvm_guest_debug_arch, dbg_bcr));
+ DEFINE(DEBUG_BVR, offsetof(struct kvm_guest_debug_arch, dbg_bvr));
+ DEFINE(DEBUG_WCR, offsetof(struct kvm_guest_debug_arch, dbg_wcr));
+ DEFINE(DEBUG_WVR, offsetof(struct kvm_guest_debug_arch, dbg_wvr));
DEFINE(VCPU_HCR_EL2, offsetof(struct kvm_vcpu, arch.hcr_el2));
DEFINE(VCPU_MDCR_EL2, offsetof(struct kvm_vcpu, arch.mdcr_el2));
DEFINE(VCPU_IRQ_LINES, offsetof(struct kvm_vcpu, arch.irq_lines));
DEFINE(VCPU_HOST_CONTEXT, offsetof(struct kvm_vcpu, arch.host_cpu_context));
+ DEFINE(VCPU_HOST_DEBUG_STATE, offsetof(struct kvm_vcpu, arch.host_debug_state));
DEFINE(VCPU_TIMER_CNTV_CTL, offsetof(struct kvm_vcpu, arch.timer_cpu.cntv_ctl));
DEFINE(VCPU_TIMER_CNTV_CVAL, offsetof(struct kvm_vcpu, arch.timer_cpu.cntv_cval));
DEFINE(KVM_TIMER_CNTVOFF, offsetof(struct kvm, arch.timer.cntvoff));
diff --git a/arch/arm64/kvm/hyp.S b/arch/arm64/kvm/hyp.S
index 335723e..d755922 100644
--- a/arch/arm64/kvm/hyp.S
+++ b/arch/arm64/kvm/hyp.S
@@ -228,7 +228,7 @@
stp x24, x25, [x3, #160]
.endm
-.macro save_debug type
+.macro save_debug type regsz offsz
// x4: pointer to register set
// x5: number of registers to skip
// x6..x22 trashed
@@ -258,22 +258,22 @@
add x22, x22, x5, lsl #2
br x22
1:
- str x21, [x4, #(15 * 8)]
- str x20, [x4, #(14 * 8)]
- str x19, [x4, #(13 * 8)]
- str x18, [x4, #(12 * 8)]
- str x17, [x4, #(11 * 8)]
- str x16, [x4, #(10 * 8)]
- str x15, [x4, #(9 * 8)]
- str x14, [x4, #(8 * 8)]
- str x13, [x4, #(7 * 8)]
- str x12, [x4, #(6 * 8)]
- str x11, [x4, #(5 * 8)]
- str x10, [x4, #(4 * 8)]
- str x9, [x4, #(3 * 8)]
- str x8, [x4, #(2 * 8)]
- str x7, [x4, #(1 * 8)]
- str x6, [x4, #(0 * 8)]
+ str \regsz\()21, [x4, #(15 * \offsz)]
+ str \regsz\()20, [x4, #(14 * \offsz)]
+ str \regsz\()19, [x4, #(13 * \offsz)]
+ str \regsz\()18, [x4, #(12 * \offsz)]
+ str \regsz\()17, [x4, #(11 * \offsz)]
+ str \regsz\()16, [x4, #(10 * \offsz)]
+ str \regsz\()15, [x4, #(9 * \offsz)]
+ str \regsz\()14, [x4, #(8 * \offsz)]
+ str \regsz\()13, [x4, #(7 * \offsz)]
+ str \regsz\()12, [x4, #(6 * \offsz)]
+ str \regsz\()11, [x4, #(5 * \offsz)]
+ str \regsz\()10, [x4, #(4 * \offsz)]
+ str \regsz\()9, [x4, #(3 * \offsz)]
+ str \regsz\()8, [x4, #(2 * \offsz)]
+ str \regsz\()7, [x4, #(1 * \offsz)]
+ str \regsz\()6, [x4, #(0 * \offsz)]
.endm
.macro restore_sysregs
@@ -318,7 +318,7 @@
msr mdscr_el1, x25
.endm
-.macro restore_debug type
+.macro restore_debug type regsz offsz
// x4: pointer to register set
// x5: number of registers to skip
// x6..x22 trashed
@@ -327,22 +327,22 @@
add x22, x22, x5, lsl #2
br x22
1:
- ldr x21, [x4, #(15 * 8)]
- ldr x20, [x4, #(14 * 8)]
- ldr x19, [x4, #(13 * 8)]
- ldr x18, [x4, #(12 * 8)]
- ldr x17, [x4, #(11 * 8)]
- ldr x16, [x4, #(10 * 8)]
- ldr x15, [x4, #(9 * 8)]
- ldr x14, [x4, #(8 * 8)]
- ldr x13, [x4, #(7 * 8)]
- ldr x12, [x4, #(6 * 8)]
- ldr x11, [x4, #(5 * 8)]
- ldr x10, [x4, #(4 * 8)]
- ldr x9, [x4, #(3 * 8)]
- ldr x8, [x4, #(2 * 8)]
- ldr x7, [x4, #(1 * 8)]
- ldr x6, [x4, #(0 * 8)]
+ ldr \regsz\()21, [x4, #(15 * \offsz)]
+ ldr \regsz\()20, [x4, #(14 * \offsz)]
+ ldr \regsz\()19, [x4, #(13 * \offsz)]
+ ldr \regsz\()18, [x4, #(12 * \offsz)]
+ ldr \regsz\()17, [x4, #(11 * \offsz)]
+ ldr \regsz\()16, [x4, #(10 * \offsz)]
+ ldr \regsz\()15, [x4, #(9 * \offsz)]
+ ldr \regsz\()14, [x4, #(8 * \offsz)]
+ ldr \regsz\()13, [x4, #(7 * \offsz)]
+ ldr \regsz\()12, [x4, #(6 * \offsz)]
+ ldr \regsz\()11, [x4, #(5 * \offsz)]
+ ldr \regsz\()10, [x4, #(4 * \offsz)]
+ ldr \regsz\()9, [x4, #(3 * \offsz)]
+ ldr \regsz\()8, [x4, #(2 * \offsz)]
+ ldr \regsz\()7, [x4, #(1 * \offsz)]
+ ldr \regsz\()6, [x4, #(0 * \offsz)]
adr x22, 1f
add x22, x22, x5, lsl #2
@@ -601,6 +601,7 @@ __restore_sysregs:
__save_debug:
// x0: base address for vcpu context
// x2: ptr to current CPU context
+ // x3: ptr to debug reg struct
// x4/x5: trashed
mrs x26, id_aa64dfr0_el1
@@ -611,16 +612,16 @@ __save_debug:
sub w25, w26, w25 // How many WPs to skip
mov x5, x24
- add x4, x2, #CPU_SYSREG_OFFSET(DBGBCR0_EL1)
- save_debug dbgbcr
- add x4, x2, #CPU_SYSREG_OFFSET(DBGBVR0_EL1)
- save_debug dbgbvr
+ add x4, x3, #DEBUG_BCR
+ save_debug dbgbcr w 4
+ add x4, x3, #DEBUG_BVR
+ save_debug dbgbvr x 8
mov x5, x25
- add x4, x2, #CPU_SYSREG_OFFSET(DBGWCR0_EL1)
- save_debug dbgwcr
- add x4, x2, #CPU_SYSREG_OFFSET(DBGWVR0_EL1)
- save_debug dbgwvr
+ add x4, x3, #DEBUG_WCR
+ save_debug dbgwcr w 4
+ add x4, x3, #DEBUG_WVR
+ save_debug dbgwvr x 8
mrs x21, mdccint_el1
str x21, [x2, #CPU_SYSREG_OFFSET(MDCCINT_EL1)]
@@ -640,16 +641,16 @@ __restore_debug:
sub w25, w26, w25 // How many WPs to skip
mov x5, x24
- add x4, x2, #CPU_SYSREG_OFFSET(DBGBCR0_EL1)
- restore_debug dbgbcr
- add x4, x2, #CPU_SYSREG_OFFSET(DBGBVR0_EL1)
- restore_debug dbgbvr
+ add x4, x3, #DEBUG_BCR
+ restore_debug dbgbcr w 4
+ add x4, x3, #DEBUG_BVR
+ restore_debug dbgbvr x 8
mov x5, x25
- add x4, x2, #CPU_SYSREG_OFFSET(DBGWCR0_EL1)
- restore_debug dbgwcr
- add x4, x2, #CPU_SYSREG_OFFSET(DBGWVR0_EL1)
- restore_debug dbgwvr
+ add x4, x3, #DEBUG_WCR
+ restore_debug dbgwcr w 4
+ add x4, x3, #DEBUG_WVR
+ restore_debug dbgwvr x 8
ldr x21, [x2, #CPU_SYSREG_OFFSET(MDCCINT_EL1)]
msr mdccint_el1, x21
@@ -688,6 +689,7 @@ ENTRY(__kvm_vcpu_run)
bl __save_sysregs
compute_debug_state 1f
+ add x3, x0, #VCPU_HOST_DEBUG_STATE
bl __save_debug
1:
activate_traps
@@ -703,6 +705,8 @@ ENTRY(__kvm_vcpu_run)
bl __restore_fpsimd
skip_debug_state x3, 1f
+ ldr x3, [x0, #VCPU_DEBUG_PTR]
+ kern_hyp_va x3
bl __restore_debug
1:
restore_guest_32bit_state
@@ -723,6 +727,8 @@ __kvm_vcpu_return:
bl __save_sysregs
skip_debug_state x3, 1f
+ ldr x3, [x0, #VCPU_DEBUG_PTR]
+ kern_hyp_va x3
bl __save_debug
1:
save_guest_32bit_state
@@ -745,6 +751,7 @@ __kvm_vcpu_return:
// already been saved. Note that we nuke the whole 64bit word.
// If we ever add more flags, we'll have to be more careful...
str xzr, [x0, #VCPU_DEBUG_FLAGS]
+ add x3, x0, #VCPU_HOST_DEBUG_STATE
bl __restore_debug
1:
restore_host_regs
diff --git a/arch/arm64/kvm/sys_regs.c b/arch/arm64/kvm/sys_regs.c
index c370b40..405403e 100644
--- a/arch/arm64/kvm/sys_regs.c
+++ b/arch/arm64/kvm/sys_regs.c
@@ -211,6 +211,48 @@ static bool trap_debug_regs(struct kvm_vcpu *vcpu,
return true;
}
+static inline bool trap_debug32(struct kvm_vcpu *vcpu,
+ const struct sys_reg_params *p,
+ const struct sys_reg_desc *rd)
+{
+ __u32 *r = (__u32 *) ((void * )&vcpu->arch.vcpu_debug_state + rd->reg);
+ if (p->is_write) {
+ *r = *vcpu_reg(vcpu, p->Rt);
+ vcpu->arch.debug_flags |= KVM_ARM64_DEBUG_DIRTY;
+ } else {
+ *vcpu_reg(vcpu, p->Rt) = *r;
+ }
+
+ return true;
+}
+
+static inline bool trap_debug64(struct kvm_vcpu *vcpu,
+ const struct sys_reg_params *p,
+ const struct sys_reg_desc *rd)
+{
+ __u64 *r = (__u64 *) ((void * )&vcpu->arch.vcpu_debug_state + rd->reg);
+ if (p->is_write) {
+ *r = *vcpu_reg(vcpu, p->Rt);
+ vcpu->arch.debug_flags |= KVM_ARM64_DEBUG_DIRTY;
+ } else {
+ *vcpu_reg(vcpu, p->Rt) = *r;
+ }
+
+ return true;
+}
+
+static inline void reset_debug32(struct kvm_vcpu *vcpu, const struct sys_reg_desc *rd)
+{
+ __u32 *r = (__u32 *) ((void * )&vcpu->arch.vcpu_debug_state + rd->reg);
+ *r = rd->val;
+}
+
+static inline void reset_debug64(struct kvm_vcpu *vcpu, const struct sys_reg_desc *rd)
+{
+ __u64 *r = (__u64 *) ((void * )&vcpu->arch.vcpu_debug_state + rd->reg);
+ *r = rd->val;
+}
+
static void reset_amair_el1(struct kvm_vcpu *vcpu, const struct sys_reg_desc *r)
{
u64 amair;
@@ -240,16 +282,20 @@ static void reset_mpidr(struct kvm_vcpu *vcpu, const struct sys_reg_desc *r)
#define DBG_BCR_BVR_WCR_WVR_EL1(n) \
/* DBGBVRn_EL1 */ \
{ Op0(0b10), Op1(0b000), CRn(0b0000), CRm((n)), Op2(0b100), \
- trap_debug_regs, reset_val, (DBGBVR0_EL1 + (n)), 0 }, \
+ trap_debug64, reset_debug64, \
+ offsetof(struct kvm_guest_debug_arch, dbg_bvr[(n)]), 0 }, \
/* DBGBCRn_EL1 */ \
{ Op0(0b10), Op1(0b000), CRn(0b0000), CRm((n)), Op2(0b101), \
- trap_debug_regs, reset_val, (DBGBCR0_EL1 + (n)), 0 }, \
+ trap_debug32, reset_debug32, \
+ offsetof(struct kvm_guest_debug_arch, dbg_bcr[(n)]), 0}, \
/* DBGWVRn_EL1 */ \
{ Op0(0b10), Op1(0b000), CRn(0b0000), CRm((n)), Op2(0b110), \
- trap_debug_regs, reset_val, (DBGWVR0_EL1 + (n)), 0 }, \
+ trap_debug64, reset_debug64, \
+ offsetof(struct kvm_guest_debug_arch, dbg_wvr[(n)]), 0 }, \
/* DBGWCRn_EL1 */ \
{ Op0(0b10), Op1(0b000), CRn(0b0000), CRm((n)), Op2(0b111), \
- trap_debug_regs, reset_val, (DBGWCR0_EL1 + (n)), 0 }
+ trap_debug32, reset_debug32, \
+ offsetof(struct kvm_guest_debug_arch, dbg_wcr[(n)]), 0}
/*
* Architected system registers.
@@ -502,37 +548,23 @@ static bool trap_dbgidr(struct kvm_vcpu *vcpu,
}
}
-static bool trap_debug32(struct kvm_vcpu *vcpu,
- const struct sys_reg_params *p,
- const struct sys_reg_desc *r)
-{
- if (p->is_write) {
- vcpu_cp14(vcpu, r->reg) = *vcpu_reg(vcpu, p->Rt);
- vcpu->arch.debug_flags |= KVM_ARM64_DEBUG_DIRTY;
- } else {
- *vcpu_reg(vcpu, p->Rt) = vcpu_cp14(vcpu, r->reg);
- }
-
- return true;
-}
-
#define DBG_BCR_BVR_WCR_WVR(n) \
/* DBGBVRn */ \
{ Op1( 0), CRn( 0), CRm((n)), Op2( 4), trap_debug32, \
- NULL, (cp14_DBGBVR0 + (n) * 2) }, \
+ NULL, offsetof(struct kvm_guest_debug_arch, dbg_bvr[(n)]) }, \
/* DBGBCRn */ \
{ Op1( 0), CRn( 0), CRm((n)), Op2( 5), trap_debug32, \
- NULL, (cp14_DBGBCR0 + (n) * 2) }, \
+ NULL, offsetof(struct kvm_guest_debug_arch, dbg_bcr[(n)]) }, \
/* DBGWVRn */ \
{ Op1( 0), CRn( 0), CRm((n)), Op2( 6), trap_debug32, \
- NULL, (cp14_DBGWVR0 + (n) * 2) }, \
+ NULL, offsetof(struct kvm_guest_debug_arch, dbg_wvr[(n)]) }, \
/* DBGWCRn */ \
{ Op1( 0), CRn( 0), CRm((n)), Op2( 7), trap_debug32, \
- NULL, (cp14_DBGWCR0 + (n) * 2) }
+ NULL, offsetof(struct kvm_guest_debug_arch, dbg_wcr[(n)]) }
#define DBGBXVR(n) \
{ Op1( 0), CRn( 1), CRm((n)), Op2( 1), trap_debug32, \
- NULL, cp14_DBGBXVR0 + n * 2 }
+ NULL, offsetof(struct kvm_guest_debug_arch, dbg_bvr[(n)])+sizeof(__u32) }
/*
* Trapped cp14 registers. We generally ignore most of the external
@@ -1288,6 +1320,42 @@ static int demux_c15_set(u64 id, void __user *uaddr)
}
}
+static int debug_set32(struct kvm_vcpu *vcpu, const struct sys_reg_desc *rd,
+ const struct kvm_one_reg *reg, void __user *uaddr)
+{
+ __u32 *r = (__u32 *) ((void * )&vcpu->arch.vcpu_debug_state + rd->reg);
+ if (copy_from_user(uaddr, r, KVM_REG_SIZE(reg->id)) != 0)
+ return -EFAULT;
+ return 0;
+}
+
+static int debug_set64(struct kvm_vcpu *vcpu, const struct sys_reg_desc *rd,
+ const struct kvm_one_reg *reg, void __user *uaddr)
+{
+ __u64 *r = (__u64 *) ((void * )&vcpu->arch.vcpu_debug_state + rd->reg);
+ if (copy_from_user(uaddr, r, KVM_REG_SIZE(reg->id)) != 0)
+ return -EFAULT;
+ return 0;
+}
+
+static int debug_get32(struct kvm_vcpu *vcpu, const struct sys_reg_desc *rd,
+ const struct kvm_one_reg *reg, void __user *uaddr)
+{
+ __u32 *r = (__u32 *) ((void * )&vcpu->arch.vcpu_debug_state + rd->reg);
+ if (copy_to_user(uaddr, r, KVM_REG_SIZE(reg->id)) != 0)
+ return -EFAULT;
+ return 0;
+}
+
+static int debug_get64(struct kvm_vcpu *vcpu, const struct sys_reg_desc *rd,
+ const struct kvm_one_reg *reg, void __user *uaddr)
+{
+ __u64 *r = (__u64 *) ((void * )&vcpu->arch.vcpu_debug_state + rd->reg);
+ if (copy_to_user(uaddr, r, KVM_REG_SIZE(reg->id)) != 0)
+ return -EFAULT;
+ return 0;
+}
+
int kvm_arm_sys_reg_get_reg(struct kvm_vcpu *vcpu, const struct kvm_one_reg *reg)
{
const struct sys_reg_desc *r;
@@ -1303,6 +1371,12 @@ int kvm_arm_sys_reg_get_reg(struct kvm_vcpu *vcpu, const struct kvm_one_reg *reg
if (!r)
return get_invariant_sys_reg(reg->id, uaddr);
+ if (r->access == trap_debug64)
+ return debug_get64(vcpu, r, reg, uaddr);
+
+ if (r->access == trap_debug32)
+ return debug_get32(vcpu, r, reg, uaddr);
+
return reg_to_user(uaddr, &vcpu_sys_reg(vcpu, r->reg), reg->id);
}
@@ -1321,6 +1395,12 @@ int kvm_arm_sys_reg_set_reg(struct kvm_vcpu *vcpu, const struct kvm_one_reg *reg
if (!r)
return set_invariant_sys_reg(reg->id, uaddr);
+ if (r->access == trap_debug64)
+ return debug_set64(vcpu, r, reg, uaddr);
+
+ if (r->access == trap_debug32)
+ return debug_set32(vcpu, r, reg, uaddr);
+
return reg_from_user(&vcpu_sys_reg(vcpu, r->reg), uaddr, reg->id);
}
--
2.3.5