From: Thomas Huth <th...@linux.vnet.ibm.com>
Add code to make use of the new ioctl for reading from / writing to
virtual guest memory. By using the ioctl, the memory accesses are now
protected with the so-called ipte-lock in the kernel.
Signed-off-by: Thomas Huth <th...@linux.vnet.ibm.com>
Signed-off-by: Cornelia Huck <cornelia.h...@de.ibm.com>
---
target-s390x/cpu.h | 7 +++++++
target-s390x/kvm.c | 35 +++++++++++++++++++++++++++++++++++
target-s390x/mmu_helper.c | 9 +++++++++
3 files changed, 51 insertions(+)
diff --git a/target-s390x/cpu.h b/target-s390x/cpu.h
index 79bc80b..9c42743 100644
--- a/target-s390x/cpu.h
+++ b/target-s390x/cpu.h
@@ -401,6 +401,8 @@ void kvm_s390_vcpu_interrupt(S390CPU *cpu, struct
kvm_s390_irq *irq);
void kvm_s390_floating_interrupt(struct kvm_s390_irq *irq);
int kvm_s390_inject_flic(struct kvm_s390_irq *irq);
void kvm_s390_access_exception(S390CPU *cpu, uint16_t code, uint64_t te_code);
+int kvm_s390_mem_op(S390CPU *cpu, vaddr addr, void *hostbuf, int len,
+ bool is_write);
int kvm_s390_get_clock(uint8_t *tod_high, uint64_t *tod_clock);
int kvm_s390_set_clock(uint8_t *tod_high, uint64_t *tod_clock);
#else
@@ -418,6 +420,11 @@ static inline int kvm_s390_set_clock(uint8_t *tod_high,
uint64_t *tod_low)
{
return -ENOSYS;
}
+static inline int kvm_s390_mem_op(S390CPU *cpu, vaddr addr, void *hostbuf,
+ int len, bool is_write)
+{
+ return -ENOSYS;
+}
static inline void kvm_s390_access_exception(S390CPU *cpu, uint16_t code,
uint64_t te_code)
{
diff --git a/target-s390x/kvm.c b/target-s390x/kvm.c
index 619684b..e2ae2b3 100644
--- a/target-s390x/kvm.c
+++ b/target-s390x/kvm.c
@@ -123,6 +123,7 @@ const KVMCapabilityInfo kvm_arch_required_capabilities[] = {
static int cap_sync_regs;
static int cap_async_pf;
+static int cap_mem_op;
static void *legacy_s390_alloc(size_t size, uint64_t *align);
@@ -247,6 +248,7 @@ int kvm_arch_init(MachineState *ms, KVMState *s)
{
cap_sync_regs = kvm_check_extension(s, KVM_CAP_SYNC_REGS);
cap_async_pf = kvm_check_extension(s, KVM_CAP_ASYNC_PF);
+ cap_mem_op = kvm_check_extension(s, KVM_CAP_S390_MEM_OP);
kvm_s390_enable_cmma(s);
@@ -550,6 +552,39 @@ int kvm_s390_set_clock(uint8_t *tod_high, uint64_t
*tod_low)
return kvm_vm_ioctl(kvm_state, KVM_SET_DEVICE_ATTR, &attr);
}
+/**
+ * kvm_s390_mem_op:
+ * @addr: the logical start address in guest memory
+ * @hostbuf: buffer in host memory. NULL = do only checks w/o copying
+ * @len: length that should be transfered
+ * @is_write: true = write, false = read
+ * Returns: 0 on success, non-zero if an exception or error occured
+ *
+ * Use KVM ioctl to read/write from/to guest memory. An access exception
+ * is injected into the vCPU in case of translation errors.
+ */
+int kvm_s390_mem_op(S390CPU *cpu, vaddr addr, void *hostbuf, int len,
+ bool is_write)
+{
+ struct kvm_s390_mem_op mem_op = {
+ .gaddr = addr,
+ .flags = KVM_S390_MEMOP_F_INJECT_EXCEPTION,
+ .size = len,
+ .op = is_write ? KVM_S390_MEMOP_LOGICAL_WRITE
+ : KVM_S390_MEMOP_LOGICAL_READ,
+ .buf = (uint64_t)hostbuf,
+ };
+
+ if (!cap_mem_op) {
+ return -ENOSYS;
+ }
+ if (!hostbuf) {
+ mem_op.flags |= KVM_S390_MEMOP_F_CHECK_ONLY;
+ }
+
+ return kvm_vcpu_ioctl(CPU(cpu), KVM_S390_MEM_OP, &mem_op);
+}
+
/*
* Legacy layout for s390:
* Older S390 KVM requires the topmost vma of the RAM to be
diff --git a/target-s390x/mmu_helper.c b/target-s390x/mmu_helper.c
index 9b88498..1e7412c 100644
--- a/target-s390x/mmu_helper.c
+++ b/target-s390x/mmu_helper.c
@@ -450,6 +450,15 @@ int s390_cpu_virt_mem_rw(S390CPU *cpu, vaddr laddr, void
*hostbuf,
target_ulong *pages;
int ret;
+ if (kvm_enabled()) {
+ ret = kvm_s390_mem_op(cpu, laddr, hostbuf, len, is_write);
+ if (ret >= 0) {
+ return ret;
+ } else if (ret != -ENOSYS) {
+ error_printf("kvm_s390_mem_op() failed: %s\n", strerror(-ret));
+ }
+ }
+
nr_pages = (((laddr & ~TARGET_PAGE_MASK) + len - 1) >> TARGET_PAGE_BITS)
+ 1;
pages = g_malloc(nr_pages * sizeof(*pages));
--
2.3.5
