Commit 84e690bf authored by Alex Bennée's avatar Alex Bennée Committed by Marc Zyngier

KVM: arm64: introduce vcpu->arch.debug_ptr

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. The new kvm_arm_reset_debug_ptr() sets the debug ptr to the
guest context.

Because we no longer give the sys_regs offset for the sys_reg_desc->reg
field, but instead the index into a debug-specific struct we need to
add a number of additional trap functions for each register. Also as the
generic generic user-space access code no longer works we have
introduced a new pair of function pointers to the sys_reg_desc structure
to override the generic code when needed.
Reviewed-by: default avatarChristoffer Dall <christoffer.dall@linaro.org>
Signed-off-by: default avatarAlex Bennée <alex.bennee@linaro.org>
Signed-off-by: default avatarMarc Zyngier <marc.zyngier@arm.com>
parent e0a1b9a9
......@@ -234,5 +234,6 @@ static inline void kvm_arch_sched_in(struct kvm_vcpu *vcpu, int cpu) {}
static inline void kvm_arm_init_debug(void) {}
static inline void kvm_arm_setup_debug(struct kvm_vcpu *vcpu) {}
static inline void kvm_arm_clear_debug(struct kvm_vcpu *vcpu) {}
static inline void kvm_arm_reset_debug_ptr(struct kvm_vcpu *vcpu) {}
#endif /* __ARM_KVM_HOST_H__ */
......@@ -278,6 +278,8 @@ int kvm_arch_vcpu_init(struct kvm_vcpu *vcpu)
/* Set up the timer */
kvm_timer_vcpu_init(vcpu);
kvm_arm_reset_debug_ptr(vcpu);
return 0;
}
......
......@@ -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 */
......
......@@ -108,11 +108,25 @@ struct kvm_vcpu_arch {
/* Exception Information */
struct kvm_vcpu_fault_info fault;
/* Debug state */
/* Guest debug state */
u64 debug_flags;
/*
* We maintain more than a single set of debug registers to support
* debugging the guest from the host and to maintain separate host and
* guest state during world switches. vcpu_debug_state are the debug
* registers of the vcpu as the guest sees them. host_debug_state are
* the host registers which are saved and restored during world switches.
*
* debug_ptr points to the set of debug registers that should be loaded
* onto the hardware when running the guest.
*/
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;
......@@ -242,5 +256,6 @@ static inline void kvm_arch_sched_in(struct kvm_vcpu *vcpu, int cpu) {}
void kvm_arm_init_debug(void);
void kvm_arm_setup_debug(struct kvm_vcpu *vcpu);
void kvm_arm_clear_debug(struct kvm_vcpu *vcpu);
void kvm_arm_reset_debug_ptr(struct kvm_vcpu *vcpu);
#endif /* __ARM64_KVM_HOST_H__ */
......@@ -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));
......
......@@ -66,6 +66,15 @@ void kvm_arm_init_debug(void)
__this_cpu_write(mdcr_el2, kvm_call_hyp(__kvm_get_mdcr_el2));
}
/**
* kvm_arm_reset_debug_ptr - reset the debug ptr to point to the vcpu state
*/
void kvm_arm_reset_debug_ptr(struct kvm_vcpu *vcpu)
{
vcpu->arch.debug_ptr = &vcpu->arch.vcpu_debug_state;
}
/**
* kvm_arm_setup_debug - set up debug related stuff
*
......
......@@ -596,6 +596,7 @@ __restore_sysregs:
/* Save debug state */
__save_debug:
// x2: ptr to CPU context
// x3: ptr to debug reg struct
// x4/x5/x6-22/x24-26: trashed
mrs x26, id_aa64dfr0_el1
......@@ -606,15 +607,15 @@ __save_debug:
sub w25, w26, w25 // How many WPs to skip
mov x5, x24
add x4, x2, #CPU_SYSREG_OFFSET(DBGBCR0_EL1)
add x4, x3, #DEBUG_BCR
save_debug dbgbcr
add x4, x2, #CPU_SYSREG_OFFSET(DBGBVR0_EL1)
add x4, x3, #DEBUG_BVR
save_debug dbgbvr
mov x5, x25
add x4, x2, #CPU_SYSREG_OFFSET(DBGWCR0_EL1)
add x4, x3, #DEBUG_WCR
save_debug dbgwcr
add x4, x2, #CPU_SYSREG_OFFSET(DBGWVR0_EL1)
add x4, x3, #DEBUG_WVR
save_debug dbgwvr
mrs x21, mdccint_el1
......@@ -624,6 +625,7 @@ __save_debug:
/* Restore debug state */
__restore_debug:
// x2: ptr to CPU context
// x3: ptr to debug reg struct
// x4/x5/x6-22/x24-26: trashed
mrs x26, id_aa64dfr0_el1
......@@ -634,15 +636,15 @@ __restore_debug:
sub w25, w26, w25 // How many WPs to skip
mov x5, x24
add x4, x2, #CPU_SYSREG_OFFSET(DBGBCR0_EL1)
add x4, x3, #DEBUG_BCR
restore_debug dbgbcr
add x4, x2, #CPU_SYSREG_OFFSET(DBGBVR0_EL1)
add x4, x3, #DEBUG_BVR
restore_debug dbgbvr
mov x5, x25
add x4, x2, #CPU_SYSREG_OFFSET(DBGWCR0_EL1)
add x4, x3, #DEBUG_WCR
restore_debug dbgwcr
add x4, x2, #CPU_SYSREG_OFFSET(DBGWVR0_EL1)
add x4, x3, #DEBUG_WVR
restore_debug dbgwvr
ldr x21, [x2, #CPU_SYSREG_OFFSET(MDCCINT_EL1)]
......@@ -682,6 +684,7 @@ ENTRY(__kvm_vcpu_run)
bl __save_sysregs
compute_debug_state 1f
add x3, x0, #VCPU_HOST_DEBUG_STATE
bl __save_debug
1:
activate_traps
......@@ -697,6 +700,8 @@ 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
......@@ -717,6 +722,8 @@ __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
......@@ -739,6 +746,7 @@ __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
......
......@@ -211,6 +211,203 @@ static bool trap_debug_regs(struct kvm_vcpu *vcpu,
return true;
}
/*
* reg_to_dbg/dbg_to_reg
*
* A 32 bit write to a debug register leave top bits alone
* A 32 bit read from a debug register only returns the bottom bits
*
* All writes will set the KVM_ARM64_DEBUG_DIRTY flag to ensure the
* hyp.S code switches between host and guest values in future.
*/
static inline void reg_to_dbg(struct kvm_vcpu *vcpu,
const struct sys_reg_params *p,
u64 *dbg_reg)
{
u64 val = *vcpu_reg(vcpu, p->Rt);
if (p->is_32bit) {
val &= 0xffffffffUL;
val |= ((*dbg_reg >> 32) << 32);
}
*dbg_reg = val;
vcpu->arch.debug_flags |= KVM_ARM64_DEBUG_DIRTY;
}
static inline void dbg_to_reg(struct kvm_vcpu *vcpu,
const struct sys_reg_params *p,
u64 *dbg_reg)
{
u64 val = *dbg_reg;
if (p->is_32bit)
val &= 0xffffffffUL;
*vcpu_reg(vcpu, p->Rt) = val;
}
static inline bool trap_bvr(struct kvm_vcpu *vcpu,
const struct sys_reg_params *p,
const struct sys_reg_desc *rd)
{
u64 *dbg_reg = &vcpu->arch.vcpu_debug_state.dbg_bvr[rd->reg];
if (p->is_write)
reg_to_dbg(vcpu, p, dbg_reg);
else
dbg_to_reg(vcpu, p, dbg_reg);
return true;
}
static int set_bvr(struct kvm_vcpu *vcpu, const struct sys_reg_desc *rd,
const struct kvm_one_reg *reg, void __user *uaddr)
{
__u64 *r = &vcpu->arch.vcpu_debug_state.dbg_bvr[rd->reg];
if (copy_from_user(uaddr, r, KVM_REG_SIZE(reg->id)) != 0)
return -EFAULT;
return 0;
}
static int get_bvr(struct kvm_vcpu *vcpu, const struct sys_reg_desc *rd,
const struct kvm_one_reg *reg, void __user *uaddr)
{
__u64 *r = &vcpu->arch.vcpu_debug_state.dbg_bvr[rd->reg];
if (copy_to_user(uaddr, r, KVM_REG_SIZE(reg->id)) != 0)
return -EFAULT;
return 0;
}
static inline void reset_bvr(struct kvm_vcpu *vcpu,
const struct sys_reg_desc *rd)
{
vcpu->arch.vcpu_debug_state.dbg_bvr[rd->reg] = rd->val;
}
static inline bool trap_bcr(struct kvm_vcpu *vcpu,
const struct sys_reg_params *p,
const struct sys_reg_desc *rd)
{
u64 *dbg_reg = &vcpu->arch.vcpu_debug_state.dbg_bcr[rd->reg];
if (p->is_write)
reg_to_dbg(vcpu, p, dbg_reg);
else
dbg_to_reg(vcpu, p, dbg_reg);
return true;
}
static int set_bcr(struct kvm_vcpu *vcpu, const struct sys_reg_desc *rd,
const struct kvm_one_reg *reg, void __user *uaddr)
{
__u64 *r = &vcpu->arch.vcpu_debug_state.dbg_bcr[rd->reg];
if (copy_from_user(uaddr, r, KVM_REG_SIZE(reg->id)) != 0)
return -EFAULT;
return 0;
}
static int get_bcr(struct kvm_vcpu *vcpu, const struct sys_reg_desc *rd,
const struct kvm_one_reg *reg, void __user *uaddr)
{
__u64 *r = &vcpu->arch.vcpu_debug_state.dbg_bcr[rd->reg];
if (copy_to_user(uaddr, r, KVM_REG_SIZE(reg->id)) != 0)
return -EFAULT;
return 0;
}
static inline void reset_bcr(struct kvm_vcpu *vcpu,
const struct sys_reg_desc *rd)
{
vcpu->arch.vcpu_debug_state.dbg_bcr[rd->reg] = rd->val;
}
static inline bool trap_wvr(struct kvm_vcpu *vcpu,
const struct sys_reg_params *p,
const struct sys_reg_desc *rd)
{
u64 *dbg_reg = &vcpu->arch.vcpu_debug_state.dbg_wvr[rd->reg];
if (p->is_write)
reg_to_dbg(vcpu, p, dbg_reg);
else
dbg_to_reg(vcpu, p, dbg_reg);
return true;
}
static int set_wvr(struct kvm_vcpu *vcpu, const struct sys_reg_desc *rd,
const struct kvm_one_reg *reg, void __user *uaddr)
{
__u64 *r = &vcpu->arch.vcpu_debug_state.dbg_wvr[rd->reg];
if (copy_from_user(uaddr, r, KVM_REG_SIZE(reg->id)) != 0)
return -EFAULT;
return 0;
}
static int get_wvr(struct kvm_vcpu *vcpu, const struct sys_reg_desc *rd,
const struct kvm_one_reg *reg, void __user *uaddr)
{
__u64 *r = &vcpu->arch.vcpu_debug_state.dbg_wvr[rd->reg];
if (copy_to_user(uaddr, r, KVM_REG_SIZE(reg->id)) != 0)
return -EFAULT;
return 0;
}
static inline void reset_wvr(struct kvm_vcpu *vcpu,
const struct sys_reg_desc *rd)
{
vcpu->arch.vcpu_debug_state.dbg_wvr[rd->reg] = rd->val;
}
static inline bool trap_wcr(struct kvm_vcpu *vcpu,
const struct sys_reg_params *p,
const struct sys_reg_desc *rd)
{
u64 *dbg_reg = &vcpu->arch.vcpu_debug_state.dbg_wcr[rd->reg];
if (p->is_write)
reg_to_dbg(vcpu, p, dbg_reg);
else
dbg_to_reg(vcpu, p, dbg_reg);
return true;
}
static int set_wcr(struct kvm_vcpu *vcpu, const struct sys_reg_desc *rd,
const struct kvm_one_reg *reg, void __user *uaddr)
{
__u64 *r = &vcpu->arch.vcpu_debug_state.dbg_wcr[rd->reg];
if (copy_from_user(uaddr, r, KVM_REG_SIZE(reg->id)) != 0)
return -EFAULT;
return 0;
}
static int get_wcr(struct kvm_vcpu *vcpu, const struct sys_reg_desc *rd,
const struct kvm_one_reg *reg, void __user *uaddr)
{
__u64 *r = &vcpu->arch.vcpu_debug_state.dbg_wcr[rd->reg];
if (copy_to_user(uaddr, r, KVM_REG_SIZE(reg->id)) != 0)
return -EFAULT;
return 0;
}
static inline void reset_wcr(struct kvm_vcpu *vcpu,
const struct sys_reg_desc *rd)
{
vcpu->arch.vcpu_debug_state.dbg_wcr[rd->reg] = rd->val;
}
static void reset_amair_el1(struct kvm_vcpu *vcpu, const struct sys_reg_desc *r)
{
u64 amair;
......@@ -240,16 +437,16 @@ 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_bvr, reset_bvr, n, 0, get_bvr, set_bvr }, \
/* DBGBCRn_EL1 */ \
{ Op0(0b10), Op1(0b000), CRn(0b0000), CRm((n)), Op2(0b101), \
trap_debug_regs, reset_val, (DBGBCR0_EL1 + (n)), 0 }, \
trap_bcr, reset_bcr, n, 0, get_bcr, set_bcr }, \
/* DBGWVRn_EL1 */ \
{ Op0(0b10), Op1(0b000), CRn(0b0000), CRm((n)), Op2(0b110), \
trap_debug_regs, reset_val, (DBGWVR0_EL1 + (n)), 0 }, \
trap_wvr, reset_wvr, n, 0, get_wvr, set_wvr }, \
/* DBGWCRn_EL1 */ \
{ Op0(0b10), Op1(0b000), CRn(0b0000), CRm((n)), Op2(0b111), \
trap_debug_regs, reset_val, (DBGWCR0_EL1 + (n)), 0 }
trap_wcr, reset_wcr, n, 0, get_wcr, set_wcr }
/*
* Architected system registers.
......@@ -516,28 +713,55 @@ static bool trap_debug32(struct kvm_vcpu *vcpu,
return true;
}
/* AArch32 debug register mappings
*
* AArch32 DBGBVRn is mapped to DBGBVRn_EL1[31:0]
* AArch32 DBGBXVRn is mapped to DBGBVRn_EL1[63:32]
*
* All control registers and watchpoint value registers are mapped to
* the lower 32 bits of their AArch64 equivalents. We share the trap
* handlers with the above AArch64 code which checks what mode the
* system is in.
*/
static inline bool trap_xvr(struct kvm_vcpu *vcpu,
const struct sys_reg_params *p,
const struct sys_reg_desc *rd)
{
u64 *dbg_reg = &vcpu->arch.vcpu_debug_state.dbg_bvr[rd->reg];
if (p->is_write) {
u64 val = *dbg_reg;
val &= 0xffffffffUL;
val |= *vcpu_reg(vcpu, p->Rt) << 32;
*dbg_reg = val;
vcpu->arch.debug_flags |= KVM_ARM64_DEBUG_DIRTY;
} else {
*vcpu_reg(vcpu, p->Rt) = *dbg_reg >> 32;
}
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) }, \
{ Op1( 0), CRn( 0), CRm((n)), Op2( 4), trap_bvr, NULL, n }, \
/* DBGBCRn */ \
{ Op1( 0), CRn( 0), CRm((n)), Op2( 5), trap_debug32, \
NULL, (cp14_DBGBCR0 + (n) * 2) }, \
{ Op1( 0), CRn( 0), CRm((n)), Op2( 5), trap_bcr, NULL, n }, \
/* DBGWVRn */ \
{ Op1( 0), CRn( 0), CRm((n)), Op2( 6), trap_debug32, \
NULL, (cp14_DBGWVR0 + (n) * 2) }, \
{ Op1( 0), CRn( 0), CRm((n)), Op2( 6), trap_wvr, NULL, n }, \
/* DBGWCRn */ \
{ Op1( 0), CRn( 0), CRm((n)), Op2( 7), trap_debug32, \
NULL, (cp14_DBGWCR0 + (n) * 2) }
{ Op1( 0), CRn( 0), CRm((n)), Op2( 7), trap_wcr, NULL, n }
#define DBGBXVR(n) \
{ Op1( 0), CRn( 1), CRm((n)), Op2( 1), trap_debug32, \
NULL, cp14_DBGBXVR0 + n * 2 }
{ Op1( 0), CRn( 1), CRm((n)), Op2( 1), trap_xvr, NULL, n }
/*
* Trapped cp14 registers. We generally ignore most of the external
* debug, on the principle that they don't really make sense to a
* guest. Revisit this one day, whould this principle change.
* guest. Revisit this one day, would this principle change.
*/
static const struct sys_reg_desc cp14_regs[] = {
/* DBGIDR */
......@@ -1303,6 +1527,9 @@ 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->get_user)
return (r->get_user)(vcpu, r, reg, uaddr);
return reg_to_user(uaddr, &vcpu_sys_reg(vcpu, r->reg), reg->id);
}
......@@ -1321,6 +1548,9 @@ 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->set_user)
return (r->set_user)(vcpu, r, reg, uaddr);
return reg_from_user(&vcpu_sys_reg(vcpu, r->reg), uaddr, reg->id);
}
......
......@@ -55,6 +55,12 @@ struct sys_reg_desc {
/* Value (usually reset value) */
u64 val;
/* Custom get/set_user functions, fallback to generic if NULL */
int (*get_user)(struct kvm_vcpu *vcpu, const struct sys_reg_desc *rd,
const struct kvm_one_reg *reg, void __user *uaddr);
int (*set_user)(struct kvm_vcpu *vcpu, const struct sys_reg_desc *rd,
const struct kvm_one_reg *reg, void __user *uaddr);
};
static inline void print_sys_reg_instr(const struct sys_reg_params *p)
......
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