diff options
| -rw-r--r-- | Documentation/virtual/kvm/api.txt | 7 | ||||
| -rw-r--r-- | arch/arm64/include/asm/hw_breakpoint.h | 14 | ||||
| -rw-r--r-- | arch/arm64/include/asm/kvm_host.h | 6 | ||||
| -rw-r--r-- | arch/arm64/kernel/hw_breakpoint.c | 12 | ||||
| -rw-r--r-- | arch/arm64/kvm/debug.c | 40 | ||||
| -rw-r--r-- | arch/arm64/kvm/guest.c | 7 | ||||
| -rw-r--r-- | arch/arm64/kvm/handle_exit.c | 6 | ||||
| -rw-r--r-- | arch/arm64/kvm/reset.c | 16 |
8 files changed, 89 insertions, 19 deletions
diff --git a/Documentation/virtual/kvm/api.txt b/Documentation/virtual/kvm/api.txt index 0f498da354f2..35affb5d9456 100644 --- a/Documentation/virtual/kvm/api.txt +++ b/Documentation/virtual/kvm/api.txt @@ -2694,7 +2694,7 @@ The top 16 bits of the control field are architecture specific control flags which can include the following: - KVM_GUESTDBG_USE_SW_BP: using software breakpoints [x86, arm64] - - KVM_GUESTDBG_USE_HW_BP: using hardware breakpoints [x86, s390] + - KVM_GUESTDBG_USE_HW_BP: using hardware breakpoints [x86, s390, arm64] - KVM_GUESTDBG_INJECT_DB: inject DB type exception [x86] - KVM_GUESTDBG_INJECT_BP: inject BP type exception [x86] - KVM_GUESTDBG_EXIT_PENDING: trigger an immediate guest exit [s390] @@ -2709,6 +2709,11 @@ updated to the correct (supplied) values. The second part of the structure is architecture specific and typically contains a set of debug registers. +For arm64 the number of debug registers is implementation defined and +can be determined by querying the KVM_CAP_GUEST_DEBUG_HW_BPS and +KVM_CAP_GUEST_DEBUG_HW_WPS capabilities which return a positive number +indicating the number of supported registers. + When debug events exit the main run loop with the reason KVM_EXIT_DEBUG with the kvm_debug_exit_arch part of the kvm_run structure containing architecture specific debug information. diff --git a/arch/arm64/include/asm/hw_breakpoint.h b/arch/arm64/include/asm/hw_breakpoint.h index 52b484b6aa1a..4c47cb2fbb52 100644 --- a/arch/arm64/include/asm/hw_breakpoint.h +++ b/arch/arm64/include/asm/hw_breakpoint.h @@ -16,6 +16,8 @@ #ifndef __ASM_HW_BREAKPOINT_H #define __ASM_HW_BREAKPOINT_H +#include <asm/cputype.h> + #ifdef __KERNEL__ struct arch_hw_breakpoint_ctrl { @@ -132,5 +134,17 @@ static inline void ptrace_hw_copy_thread(struct task_struct *task) extern struct pmu perf_ops_bp; +/* Determine number of BRP registers available. */ +static inline int get_num_brps(void) +{ + return ((read_cpuid(ID_AA64DFR0_EL1) >> 12) & 0xf) + 1; +} + +/* Determine number of WRP registers available. */ +static inline int get_num_wrps(void) +{ + return ((read_cpuid(ID_AA64DFR0_EL1) >> 20) & 0xf) + 1; +} + #endif /* __KERNEL__ */ #endif /* __ASM_BREAKPOINT_H */ diff --git a/arch/arm64/include/asm/kvm_host.h b/arch/arm64/include/asm/kvm_host.h index 9b99402b14df..409217f48456 100644 --- a/arch/arm64/include/asm/kvm_host.h +++ b/arch/arm64/include/asm/kvm_host.h @@ -116,13 +116,17 @@ struct kvm_vcpu_arch { * 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. + * the host registers which are saved and restored during + * world switches. external_debug_state contains the debug + * values we want to debug the guest. This is set via the + * KVM_SET_GUEST_DEBUG ioctl. * * 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; + struct kvm_guest_debug_arch external_debug_state; /* Pointer to host CPU context */ kvm_cpu_context_t *host_cpu_context; diff --git a/arch/arm64/kernel/hw_breakpoint.c b/arch/arm64/kernel/hw_breakpoint.c index 7a1a5da6c8c1..77bee00bd7ea 100644 --- a/arch/arm64/kernel/hw_breakpoint.c +++ b/arch/arm64/kernel/hw_breakpoint.c @@ -48,18 +48,6 @@ static DEFINE_PER_CPU(int, stepping_kernel_bp); static int core_num_brps; static int core_num_wrps; -/* Determine number of BRP registers available. */ -static int get_num_brps(void) -{ - return ((read_cpuid(ID_AA64DFR0_EL1) >> 12) & 0xf) + 1; -} - -/* Determine number of WRP registers available. */ -static int get_num_wrps(void) -{ - return ((read_cpuid(ID_AA64DFR0_EL1) >> 20) & 0xf) + 1; -} - int hw_breakpoint_slots(int type) { /* diff --git a/arch/arm64/kvm/debug.c b/arch/arm64/kvm/debug.c index e0947b77faaa..4a99e54d7f3d 100644 --- a/arch/arm64/kvm/debug.c +++ b/arch/arm64/kvm/debug.c @@ -105,10 +105,6 @@ void kvm_arm_setup_debug(struct kvm_vcpu *vcpu) MDCR_EL2_TDRA | MDCR_EL2_TDOSA); - /* Trap on access to debug registers? */ - if (trap_debug) - vcpu->arch.mdcr_el2 |= MDCR_EL2_TDA; - /* Is Guest debugging in effect? */ if (vcpu->guest_debug) { /* Route all software debug exceptions to EL2 */ @@ -143,11 +139,45 @@ void kvm_arm_setup_debug(struct kvm_vcpu *vcpu) } else { vcpu_sys_reg(vcpu, MDSCR_EL1) &= ~DBG_MDSCR_SS; } + + /* + * HW Breakpoints and watchpoints + * + * We simply switch the debug_ptr to point to our new + * external_debug_state which has been populated by the + * debug ioctl. The existing KVM_ARM64_DEBUG_DIRTY + * mechanism ensures the registers are updated on the + * world switch. + */ + if (vcpu->guest_debug & KVM_GUESTDBG_USE_HW) { + /* Enable breakpoints/watchpoints */ + vcpu_sys_reg(vcpu, MDSCR_EL1) |= DBG_MDSCR_MDE; + + vcpu->arch.debug_ptr = &vcpu->arch.external_debug_state; + vcpu->arch.debug_flags |= KVM_ARM64_DEBUG_DIRTY; + trap_debug = true; + } } + + BUG_ON(!vcpu->guest_debug && + vcpu->arch.debug_ptr != &vcpu->arch.vcpu_debug_state); + + /* Trap debug register access */ + if (trap_debug) + vcpu->arch.mdcr_el2 |= MDCR_EL2_TDA; } void kvm_arm_clear_debug(struct kvm_vcpu *vcpu) { - if (vcpu->guest_debug) + if (vcpu->guest_debug) { restore_guest_debug_regs(vcpu); + + /* + * If we were using HW debug we need to restore the + * debug_ptr to the guest debug state. + */ + if (vcpu->guest_debug & KVM_GUESTDBG_USE_HW) + kvm_arm_reset_debug_ptr(vcpu); + + } } diff --git a/arch/arm64/kvm/guest.c b/arch/arm64/kvm/guest.c index 48de4f4aaa1a..6f1b249e0587 100644 --- a/arch/arm64/kvm/guest.c +++ b/arch/arm64/kvm/guest.c @@ -334,6 +334,7 @@ int kvm_arch_vcpu_ioctl_translate(struct kvm_vcpu *vcpu, #define KVM_GUESTDBG_VALID_MASK (KVM_GUESTDBG_ENABLE | \ KVM_GUESTDBG_USE_SW_BP | \ + KVM_GUESTDBG_USE_HW | \ KVM_GUESTDBG_SINGLESTEP) /** @@ -354,6 +355,12 @@ int kvm_arch_vcpu_ioctl_set_guest_debug(struct kvm_vcpu *vcpu, if (dbg->control & KVM_GUESTDBG_ENABLE) { vcpu->guest_debug = dbg->control; + + /* Hardware assisted Break and Watch points */ + if (vcpu->guest_debug & KVM_GUESTDBG_USE_HW) { + vcpu->arch.external_debug_state = dbg->arch; + } + } else { /* If not enabled clear all flags */ vcpu->guest_debug = 0; diff --git a/arch/arm64/kvm/handle_exit.c b/arch/arm64/kvm/handle_exit.c index e9de13ed477e..68a0759b1375 100644 --- a/arch/arm64/kvm/handle_exit.c +++ b/arch/arm64/kvm/handle_exit.c @@ -103,7 +103,11 @@ static int kvm_handle_guest_debug(struct kvm_vcpu *vcpu, struct kvm_run *run) run->debug.arch.hsr = hsr; switch (hsr >> ESR_ELx_EC_SHIFT) { + case ESR_ELx_EC_WATCHPT_LOW: + run->debug.arch.far = vcpu->arch.fault.far_el2; + /* fall through */ case ESR_ELx_EC_SOFTSTP_LOW: + case ESR_ELx_EC_BREAKPT_LOW: case ESR_ELx_EC_BKPT32: case ESR_ELx_EC_BRK64: break; @@ -132,6 +136,8 @@ static exit_handle_fn arm_exit_handlers[] = { [ESR_ELx_EC_IABT_LOW] = kvm_handle_guest_abort, [ESR_ELx_EC_DABT_LOW] = kvm_handle_guest_abort, [ESR_ELx_EC_SOFTSTP_LOW]= kvm_handle_guest_debug, + [ESR_ELx_EC_WATCHPT_LOW]= kvm_handle_guest_debug, + [ESR_ELx_EC_BREAKPT_LOW]= kvm_handle_guest_debug, [ESR_ELx_EC_BKPT32] = kvm_handle_guest_debug, [ESR_ELx_EC_BRK64] = kvm_handle_guest_debug, }; diff --git a/arch/arm64/kvm/reset.c b/arch/arm64/kvm/reset.c index 0b4326578985..b4af6185713f 100644 --- a/arch/arm64/kvm/reset.c +++ b/arch/arm64/kvm/reset.c @@ -22,6 +22,7 @@ #include <linux/errno.h> #include <linux/kvm_host.h> #include <linux/kvm.h> +#include <linux/hw_breakpoint.h> #include <kvm/arm_arch_timer.h> @@ -56,6 +57,12 @@ static bool cpu_has_32bit_el1(void) return !!(pfr0 & 0x20); } +/** + * kvm_arch_dev_ioctl_check_extension + * + * We currently assume that the number of HW registers is uniform + * across all CPUs (see cpuinfo_sanity_check). + */ int kvm_arch_dev_ioctl_check_extension(long ext) { int r; @@ -64,6 +71,15 @@ int kvm_arch_dev_ioctl_check_extension(long ext) case KVM_CAP_ARM_EL1_32BIT: r = cpu_has_32bit_el1(); break; + case KVM_CAP_GUEST_DEBUG_HW_BPS: + r = get_num_brps(); + break; + case KVM_CAP_GUEST_DEBUG_HW_WPS: + r = get_num_wrps(); + break; + case KVM_CAP_SET_GUEST_DEBUG: + r = 1; + break; default: r = 0; } |