--- /dev/null
+/*
+ * kvm guest debug support
+ *
+ * Copyright IBM Corp. 2014
+ *
+ * This program is free software; you can redistribute it and/or modify
+ * it under the terms of the GNU General Public License (version 2 only)
+ * as published by the Free Software Foundation.
+ *
+ * Author(s): David Hildenbrand <dahi@linux.vnet.ibm.com>
+ */
+#include <linux/kvm_host.h>
+#include <linux/errno.h>
+#include "kvm-s390.h"
+#include "gaccess.h"
+
+/*
+ * Extends the address range given by *start and *stop to include the address
+ * range starting with estart and the length len. Takes care of overflowing
+ * intervals and tries to minimize the overall intervall size.
+ */
+static void extend_address_range(u64 *start, u64 *stop, u64 estart, int len)
+{
+ u64 estop;
+
+ if (len > 0)
+ len--;
+ else
+ len = 0;
+
+ estop = estart + len;
+
+ /* 0-0 range represents "not set" */
+ if ((*start == 0) && (*stop == 0)) {
+ *start = estart;
+ *stop = estop;
+ } else if (*start <= *stop) {
+ /* increase the existing range */
+ if (estart < *start)
+ *start = estart;
+ if (estop > *stop)
+ *stop = estop;
+ } else {
+ /* "overflowing" interval, whereby *stop > *start */
+ if (estart <= *stop) {
+ if (estop > *stop)
+ *stop = estop;
+ } else if (estop > *start) {
+ if (estart < *start)
+ *start = estart;
+ }
+ /* minimize the range */
+ else if ((estop - *stop) < (*start - estart))
+ *stop = estop;
+ else
+ *start = estart;
+ }
+}
+
+#define MAX_INST_SIZE 6
+
+static void enable_all_hw_bp(struct kvm_vcpu *vcpu)
+{
+ unsigned long start, len;
+ u64 *cr9 = &vcpu->arch.sie_block->gcr[9];
+ u64 *cr10 = &vcpu->arch.sie_block->gcr[10];
+ u64 *cr11 = &vcpu->arch.sie_block->gcr[11];
+ int i;
+
+ if (vcpu->arch.guestdbg.nr_hw_bp <= 0 ||
+ vcpu->arch.guestdbg.hw_bp_info == NULL)
+ return;
+
+ /*
+ * If the guest is not interrested in branching events, we can savely
+ * limit them to the PER address range.
+ */
+ if (!(*cr9 & PER_EVENT_BRANCH))
+ *cr9 |= PER_CONTROL_BRANCH_ADDRESS;
+ *cr9 |= PER_EVENT_IFETCH | PER_EVENT_BRANCH;
+
+ for (i = 0; i < vcpu->arch.guestdbg.nr_hw_bp; i++) {
+ start = vcpu->arch.guestdbg.hw_bp_info[i].addr;
+ len = vcpu->arch.guestdbg.hw_bp_info[i].len;
+
+ /*
+ * The instruction in front of the desired bp has to
+ * report instruction-fetching events
+ */
+ if (start < MAX_INST_SIZE) {
+ len += start;
+ start = 0;
+ } else {
+ start -= MAX_INST_SIZE;
+ len += MAX_INST_SIZE;
+ }
+
+ extend_address_range(cr10, cr11, start, len);
+ }
+}
+
+static void enable_all_hw_wp(struct kvm_vcpu *vcpu)
+{
+ unsigned long start, len;
+ u64 *cr9 = &vcpu->arch.sie_block->gcr[9];
+ u64 *cr10 = &vcpu->arch.sie_block->gcr[10];
+ u64 *cr11 = &vcpu->arch.sie_block->gcr[11];
+ int i;
+
+ if (vcpu->arch.guestdbg.nr_hw_wp <= 0 ||
+ vcpu->arch.guestdbg.hw_wp_info == NULL)
+ return;
+
+ /* if host uses storage alternation for special address
+ * spaces, enable all events and give all to the guest */
+ if (*cr9 & PER_EVENT_STORE && *cr9 & PER_CONTROL_ALTERATION) {
+ *cr9 &= ~PER_CONTROL_ALTERATION;
+ *cr10 = 0;
+ *cr11 = PSW_ADDR_INSN;
+ } else {
+ *cr9 &= ~PER_CONTROL_ALTERATION;
+ *cr9 |= PER_EVENT_STORE;
+
+ for (i = 0; i < vcpu->arch.guestdbg.nr_hw_wp; i++) {
+ start = vcpu->arch.guestdbg.hw_wp_info[i].addr;
+ len = vcpu->arch.guestdbg.hw_wp_info[i].len;
+
+ extend_address_range(cr10, cr11, start, len);
+ }
+ }
+}
+
+void kvm_s390_backup_guest_per_regs(struct kvm_vcpu *vcpu)
+{
+ vcpu->arch.guestdbg.cr0 = vcpu->arch.sie_block->gcr[0];
+ vcpu->arch.guestdbg.cr9 = vcpu->arch.sie_block->gcr[9];
+ vcpu->arch.guestdbg.cr10 = vcpu->arch.sie_block->gcr[10];
+ vcpu->arch.guestdbg.cr11 = vcpu->arch.sie_block->gcr[11];
+}
+
+void kvm_s390_restore_guest_per_regs(struct kvm_vcpu *vcpu)
+{
+ vcpu->arch.sie_block->gcr[0] = vcpu->arch.guestdbg.cr0;
+ vcpu->arch.sie_block->gcr[9] = vcpu->arch.guestdbg.cr9;
+ vcpu->arch.sie_block->gcr[10] = vcpu->arch.guestdbg.cr10;
+ vcpu->arch.sie_block->gcr[11] = vcpu->arch.guestdbg.cr11;
+}
+
+void kvm_s390_patch_guest_per_regs(struct kvm_vcpu *vcpu)
+{
+ /*
+ * TODO: if guest psw has per enabled, otherwise 0s!
+ * This reduces the amount of reported events.
+ * Need to intercept all psw changes!
+ */
+
+ if (guestdbg_sstep_enabled(vcpu)) {
+ vcpu->arch.sie_block->gcr[9] |= PER_EVENT_IFETCH;
+ vcpu->arch.sie_block->gcr[10] = 0;
+ vcpu->arch.sie_block->gcr[11] = PSW_ADDR_INSN;
+ }
+
+ if (guestdbg_hw_bp_enabled(vcpu)) {
+ enable_all_hw_bp(vcpu);
+ enable_all_hw_wp(vcpu);
+ }
+
+ /* TODO: Instruction-fetching-nullification not allowed for now */
+ if (vcpu->arch.sie_block->gcr[9] & PER_EVENT_NULLIFICATION)
+ vcpu->arch.sie_block->gcr[9] &= ~PER_EVENT_NULLIFICATION;
+}
+
+#define MAX_WP_SIZE 100
+
+static int __import_wp_info(struct kvm_vcpu *vcpu,
+ struct kvm_hw_breakpoint *bp_data,
+ struct kvm_hw_wp_info_arch *wp_info)
+{
+ int ret = 0;
+ wp_info->len = bp_data->len;
+ wp_info->addr = bp_data->addr;
+ wp_info->phys_addr = bp_data->phys_addr;
+ wp_info->old_data = NULL;
+
+ if (wp_info->len < 0 || wp_info->len > MAX_WP_SIZE)
+ return -EINVAL;
+
+ wp_info->old_data = kmalloc(bp_data->len, GFP_KERNEL);
+ if (!wp_info->old_data)
+ return -ENOMEM;
+ /* try to backup the original value */
+ ret = read_guest(vcpu, wp_info->phys_addr, wp_info->old_data,
+ wp_info->len);
+ if (ret) {
+ kfree(wp_info->old_data);
+ wp_info->old_data = NULL;
+ }
+
+ return ret;
+}
+
+#define MAX_BP_COUNT 50
+
+int kvm_s390_import_bp_data(struct kvm_vcpu *vcpu,
+ struct kvm_guest_debug *dbg)
+{
+ int ret = 0, nr_wp = 0, nr_bp = 0, i, size;
+ struct kvm_hw_breakpoint *bp_data = NULL;
+ struct kvm_hw_wp_info_arch *wp_info = NULL;
+ struct kvm_hw_bp_info_arch *bp_info = NULL;
+
+ if (dbg->arch.nr_hw_bp <= 0 || !dbg->arch.hw_bp)
+ return 0;
+ else if (dbg->arch.nr_hw_bp > MAX_BP_COUNT)
+ return -EINVAL;
+
+ size = dbg->arch.nr_hw_bp * sizeof(struct kvm_hw_breakpoint);
+ bp_data = kmalloc(size, GFP_KERNEL);
+ if (!bp_data) {
+ ret = -ENOMEM;
+ goto error;
+ }
+
+ ret = copy_from_user(bp_data, dbg->arch.hw_bp, size);
+ if (ret)
+ goto error;
+
+ for (i = 0; i < dbg->arch.nr_hw_bp; i++) {
+ switch (bp_data[i].type) {
+ case KVM_HW_WP_WRITE:
+ nr_wp++;
+ break;
+ case KVM_HW_BP:
+ nr_bp++;
+ break;
+ default:
+ break;
+ }
+ }
+
+ size = nr_wp * sizeof(struct kvm_hw_wp_info_arch);
+ if (size > 0) {
+ wp_info = kmalloc(size, GFP_KERNEL);
+ if (!wp_info) {
+ ret = -ENOMEM;
+ goto error;
+ }
+ }
+ size = nr_bp * sizeof(struct kvm_hw_bp_info_arch);
+ if (size > 0) {
+ bp_info = kmalloc(size, GFP_KERNEL);
+ if (!bp_info) {
+ ret = -ENOMEM;
+ goto error;
+ }
+ }
+
+ for (nr_wp = 0, nr_bp = 0, i = 0; i < dbg->arch.nr_hw_bp; i++) {
+ switch (bp_data[i].type) {
+ case KVM_HW_WP_WRITE:
+ ret = __import_wp_info(vcpu, &bp_data[i],
+ &wp_info[nr_wp]);
+ if (ret)
+ goto error;
+ nr_wp++;
+ break;
+ case KVM_HW_BP:
+ bp_info[nr_bp].len = bp_data[i].len;
+ bp_info[nr_bp].addr = bp_data[i].addr;
+ nr_bp++;
+ break;
+ }
+ }
+
+ vcpu->arch.guestdbg.nr_hw_bp = nr_bp;
+ vcpu->arch.guestdbg.hw_bp_info = bp_info;
+ vcpu->arch.guestdbg.nr_hw_wp = nr_wp;
+ vcpu->arch.guestdbg.hw_wp_info = wp_info;
+ return 0;
+error:
+ kfree(bp_data);
+ kfree(wp_info);
+ kfree(bp_info);
+ return ret;
+}
+
+void kvm_s390_clear_bp_data(struct kvm_vcpu *vcpu)
+{
+ int i;
+ struct kvm_hw_wp_info_arch *hw_wp_info = NULL;
+
+ for (i = 0; i < vcpu->arch.guestdbg.nr_hw_wp; i++) {
+ hw_wp_info = &vcpu->arch.guestdbg.hw_wp_info[i];
+ kfree(hw_wp_info->old_data);
+ hw_wp_info->old_data = NULL;
+ }
+ kfree(vcpu->arch.guestdbg.hw_wp_info);
+ vcpu->arch.guestdbg.hw_wp_info = NULL;
+
+ kfree(vcpu->arch.guestdbg.hw_bp_info);
+ vcpu->arch.guestdbg.hw_bp_info = NULL;
+
+ vcpu->arch.guestdbg.nr_hw_wp = 0;
+ vcpu->arch.guestdbg.nr_hw_bp = 0;
+}
+
+static inline int in_addr_range(u64 addr, u64 a, u64 b)
+{
+ if (a <= b)
+ return (addr >= a) && (addr <= b);
+ else
+ /* "overflowing" interval */
+ return (addr <= a) && (addr >= b);
+}
+
+#define end_of_range(bp_info) (bp_info->addr + bp_info->len - 1)
+
+static struct kvm_hw_bp_info_arch *find_hw_bp(struct kvm_vcpu *vcpu,
+ unsigned long addr)
+{
+ struct kvm_hw_bp_info_arch *bp_info = vcpu->arch.guestdbg.hw_bp_info;
+ int i;
+
+ if (vcpu->arch.guestdbg.nr_hw_bp == 0)
+ return NULL;
+
+ for (i = 0; i < vcpu->arch.guestdbg.nr_hw_bp; i++) {
+ /* addr is directly the start or in the range of a bp */
+ if (addr == bp_info->addr)
+ goto found;
+ if (bp_info->len > 0 &&
+ in_addr_range(addr, bp_info->addr, end_of_range(bp_info)))
+ goto found;
+
+ bp_info++;
+ }
+
+ return NULL;
+found:
+ return bp_info;
+}
+
+static struct kvm_hw_wp_info_arch *any_wp_changed(struct kvm_vcpu *vcpu)
+{
+ int i;
+ struct kvm_hw_wp_info_arch *wp_info = NULL;
+ void *temp = NULL;
+
+ if (vcpu->arch.guestdbg.nr_hw_wp == 0)
+ return NULL;
+
+ for (i = 0; i < vcpu->arch.guestdbg.nr_hw_wp; i++) {
+ wp_info = &vcpu->arch.guestdbg.hw_wp_info[i];
+ if (!wp_info || !wp_info->old_data || wp_info->len <= 0)
+ continue;
+
+ temp = kmalloc(wp_info->len, GFP_KERNEL);
+ if (!temp)
+ continue;
+
+ /* refetch the wp data and compare it to the old value */
+ if (!read_guest(vcpu, wp_info->phys_addr, temp,
+ wp_info->len)) {
+ if (memcmp(temp, wp_info->old_data, wp_info->len)) {
+ kfree(temp);
+ return wp_info;
+ }
+ }
+ kfree(temp);
+ temp = NULL;
+ }
+
+ return NULL;
+}
+
+void kvm_s390_prepare_debug_exit(struct kvm_vcpu *vcpu)
+{
+ vcpu->run->exit_reason = KVM_EXIT_DEBUG;
+ vcpu->guest_debug &= ~KVM_GUESTDBG_EXIT_PENDING;
+}
+
+#define per_bp_event(code) \
+ (code & (PER_EVENT_IFETCH | PER_EVENT_BRANCH))
+#define per_write_wp_event(code) \
+ (code & (PER_EVENT_STORE | PER_EVENT_STORE_REAL))
+
+static int debug_exit_required(struct kvm_vcpu *vcpu)
+{
+ u32 perc = (vcpu->arch.sie_block->perc << 24);
+ struct kvm_debug_exit_arch *debug_exit = &vcpu->run->debug.arch;
+ struct kvm_hw_wp_info_arch *wp_info = NULL;
+ struct kvm_hw_bp_info_arch *bp_info = NULL;
+ unsigned long addr = vcpu->arch.sie_block->gpsw.addr;
+ unsigned long peraddr = vcpu->arch.sie_block->peraddr;
+
+ if (guestdbg_hw_bp_enabled(vcpu)) {
+ if (per_write_wp_event(perc) &&
+ vcpu->arch.guestdbg.nr_hw_wp > 0) {
+ wp_info = any_wp_changed(vcpu);
+ if (wp_info) {
+ debug_exit->addr = wp_info->addr;
+ debug_exit->type = KVM_HW_WP_WRITE;
+ goto exit_required;
+ }
+ }
+ if (per_bp_event(perc) &&
+ vcpu->arch.guestdbg.nr_hw_bp > 0) {
+ bp_info = find_hw_bp(vcpu, addr);
+ /* remove duplicate events if PC==PER address */
+ if (bp_info && (addr != peraddr)) {
+ debug_exit->addr = addr;
+ debug_exit->type = KVM_HW_BP;
+ vcpu->arch.guestdbg.last_bp = addr;
+ goto exit_required;
+ }
+ /* breakpoint missed */
+ bp_info = find_hw_bp(vcpu, peraddr);
+ if (bp_info && vcpu->arch.guestdbg.last_bp != peraddr) {
+ debug_exit->addr = peraddr;
+ debug_exit->type = KVM_HW_BP;
+ goto exit_required;
+ }
+ }
+ }
+ if (guestdbg_sstep_enabled(vcpu) && per_bp_event(perc)) {
+ debug_exit->addr = addr;
+ debug_exit->type = KVM_SINGLESTEP;
+ goto exit_required;
+ }
+
+ return 0;
+exit_required:
+ return 1;
+}
+
+#define guest_per_enabled(vcpu) \
+ (vcpu->arch.sie_block->gpsw.mask & PSW_MASK_PER)
+
+static void filter_guest_per_event(struct kvm_vcpu *vcpu)
+{
+ u32 perc = vcpu->arch.sie_block->perc << 24;
+ u64 peraddr = vcpu->arch.sie_block->peraddr;
+ u64 addr = vcpu->arch.sie_block->gpsw.addr;
+ u64 cr9 = vcpu->arch.sie_block->gcr[9];
+ u64 cr10 = vcpu->arch.sie_block->gcr[10];
+ u64 cr11 = vcpu->arch.sie_block->gcr[11];
+ /* filter all events, demanded by the guest */
+ u32 guest_perc = perc & cr9 & PER_EVENT_MASK;
+
+ if (!guest_per_enabled(vcpu))
+ guest_perc = 0;
+
+ /* filter "successful-branching" events */
+ if (guest_perc & PER_EVENT_BRANCH &&
+ cr9 & PER_CONTROL_BRANCH_ADDRESS &&
+ !in_addr_range(addr, cr10, cr11))
+ guest_perc &= ~PER_EVENT_BRANCH;
+
+ /* filter "instruction-fetching" events */
+ if (guest_perc & PER_EVENT_IFETCH &&
+ !in_addr_range(peraddr, cr10, cr11))
+ guest_perc &= ~PER_EVENT_IFETCH;
+
+ /* All other PER events will be given to the guest */
+ /* TODO: Check alterated address/address space */
+
+ vcpu->arch.sie_block->perc = guest_perc >> 24;
+
+ if (!guest_perc)
+ vcpu->arch.sie_block->iprcc &= ~PGM_PER;
+}
+
+void kvm_s390_handle_per_event(struct kvm_vcpu *vcpu)
+{
+ if (debug_exit_required(vcpu))
+ vcpu->guest_debug |= KVM_GUESTDBG_EXIT_PENDING;
+
+ filter_guest_per_event(vcpu);
+}
return -EINVAL; /* not implemented yet */
}
+#define VALID_GUESTDBG_FLAGS (KVM_GUESTDBG_SINGLESTEP | \
+ KVM_GUESTDBG_USE_HW_BP | \
+ KVM_GUESTDBG_ENABLE)
+
int kvm_arch_vcpu_ioctl_set_guest_debug(struct kvm_vcpu *vcpu,
struct kvm_guest_debug *dbg)
{
- return -EINVAL; /* not implemented yet */
+ int rc = 0;
+
+ vcpu->guest_debug = 0;
+ kvm_s390_clear_bp_data(vcpu);
+
+ if (vcpu->guest_debug & ~VALID_GUESTDBG_FLAGS)
+ return -EINVAL;
+
+ if (dbg->control & KVM_GUESTDBG_ENABLE) {
+ vcpu->guest_debug = dbg->control;
+ /* enforce guest PER */
+ atomic_set_mask(CPUSTAT_P, &vcpu->arch.sie_block->cpuflags);
+
+ if (dbg->control & KVM_GUESTDBG_USE_HW_BP)
+ rc = kvm_s390_import_bp_data(vcpu, dbg);
+ } else {
+ atomic_clear_mask(CPUSTAT_P, &vcpu->arch.sie_block->cpuflags);
+ vcpu->arch.guestdbg.last_bp = 0;
+ }
+
+ if (rc) {
+ vcpu->guest_debug = 0;
+ kvm_s390_clear_bp_data(vcpu);
+ atomic_clear_mask(CPUSTAT_P, &vcpu->arch.sie_block->cpuflags);
+ }
+
+ return rc;
}
int kvm_arch_vcpu_ioctl_get_mpstate(struct kvm_vcpu *vcpu,
if (rc)
return rc;
+ if (guestdbg_enabled(vcpu)) {
+ kvm_s390_backup_guest_per_regs(vcpu);
+ kvm_s390_patch_guest_per_regs(vcpu);
+ }
+
vcpu->arch.sie_block->icptcode = 0;
cpuflags = atomic_read(&vcpu->arch.sie_block->cpuflags);
VCPU_EVENT(vcpu, 6, "entering sie flags %x", cpuflags);
vcpu->arch.sie_block->icptcode);
trace_kvm_s390_sie_exit(vcpu, vcpu->arch.sie_block->icptcode);
+ if (guestdbg_enabled(vcpu))
+ kvm_s390_restore_guest_per_regs(vcpu);
+
if (exit_reason >= 0) {
rc = 0;
} else if (kvm_is_ucontrol(vcpu->kvm)) {
vcpu->srcu_idx = srcu_read_lock(&vcpu->kvm->srcu);
rc = vcpu_post_run(vcpu, exit_reason);
- } while (!signal_pending(current) && !rc);
+ } while (!signal_pending(current) && !guestdbg_exit_pending(vcpu) && !rc);
srcu_read_unlock(&vcpu->kvm->srcu, vcpu->srcu_idx);
return rc;
int rc;
sigset_t sigsaved;
+ if (guestdbg_exit_pending(vcpu)) {
+ kvm_s390_prepare_debug_exit(vcpu);
+ return 0;
+ }
+
if (vcpu->sigset_active)
sigprocmask(SIG_SETMASK, &vcpu->sigset, &sigsaved);
case KVM_EXIT_S390_RESET:
case KVM_EXIT_S390_UCONTROL:
case KVM_EXIT_S390_TSCH:
+ case KVM_EXIT_DEBUG:
break;
default:
BUG();
rc = -EINTR;
}
+ if (guestdbg_exit_pending(vcpu) && !rc) {
+ kvm_s390_prepare_debug_exit(vcpu);
+ rc = 0;
+ }
+
if (rc == -EOPNOTSUPP) {
/* intercept cannot be handled in-kernel, prepare kvm-run */
kvm_run->exit_reason = KVM_EXIT_S390_SIEIC;
git.openpandora.org / pandora-kernel.git / commitdiff