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-rw-r--r--arch/ia64/include/asm/kvm_host.h2
-rw-r--r--arch/ia64/kvm/kvm-ia64.c10
-rw-r--r--arch/x86/kvm/x86.c114
-rw-r--r--include/linux/kvm_host.h31
4 files changed, 115 insertions, 42 deletions
diff --git a/arch/ia64/include/asm/kvm_host.h b/arch/ia64/include/asm/kvm_host.h
index c4b4bac3d09e..6d6a5ac48d85 100644
--- a/arch/ia64/include/asm/kvm_host.h
+++ b/arch/ia64/include/asm/kvm_host.h
@@ -449,6 +449,8 @@ struct kvm_vcpu_arch {
char log_buf[VMM_LOG_LEN];
union context host;
union context guest;
+
+ char mmio_data[8];
};
struct kvm_vm_stat {
diff --git a/arch/ia64/kvm/kvm-ia64.c b/arch/ia64/kvm/kvm-ia64.c
index 9d80ff8d9eff..882ab21a8dcd 100644
--- a/arch/ia64/kvm/kvm-ia64.c
+++ b/arch/ia64/kvm/kvm-ia64.c
@@ -232,12 +232,12 @@ static int handle_mmio(struct kvm_vcpu *vcpu, struct kvm_run *kvm_run)
if ((p->addr & PAGE_MASK) == IOAPIC_DEFAULT_BASE_ADDRESS)
goto mmio;
vcpu->mmio_needed = 1;
- vcpu->mmio_phys_addr = kvm_run->mmio.phys_addr = p->addr;
- vcpu->mmio_size = kvm_run->mmio.len = p->size;
+ vcpu->mmio_fragments[0].gpa = kvm_run->mmio.phys_addr = p->addr;
+ vcpu->mmio_fragments[0].len = kvm_run->mmio.len = p->size;
vcpu->mmio_is_write = kvm_run->mmio.is_write = !p->dir;
if (vcpu->mmio_is_write)
- memcpy(vcpu->mmio_data, &p->data, p->size);
+ memcpy(vcpu->arch.mmio_data, &p->data, p->size);
memcpy(kvm_run->mmio.data, &p->data, p->size);
kvm_run->exit_reason = KVM_EXIT_MMIO;
return 0;
@@ -719,7 +719,7 @@ static void kvm_set_mmio_data(struct kvm_vcpu *vcpu)
struct kvm_mmio_req *p = kvm_get_vcpu_ioreq(vcpu);
if (!vcpu->mmio_is_write)
- memcpy(&p->data, vcpu->mmio_data, 8);
+ memcpy(&p->data, vcpu->arch.mmio_data, 8);
p->state = STATE_IORESP_READY;
}
@@ -739,7 +739,7 @@ int kvm_arch_vcpu_ioctl_run(struct kvm_vcpu *vcpu, struct kvm_run *kvm_run)
}
if (vcpu->mmio_needed) {
- memcpy(vcpu->mmio_data, kvm_run->mmio.data, 8);
+ memcpy(vcpu->arch.mmio_data, kvm_run->mmio.data, 8);
kvm_set_mmio_data(vcpu);
vcpu->mmio_read_completed = 1;
vcpu->mmio_needed = 0;
diff --git a/arch/x86/kvm/x86.c b/arch/x86/kvm/x86.c
index 0d9a57875f0b..4de705cdcafd 100644
--- a/arch/x86/kvm/x86.c
+++ b/arch/x86/kvm/x86.c
@@ -3718,9 +3718,8 @@ struct read_write_emulator_ops {
static int read_prepare(struct kvm_vcpu *vcpu, void *val, int bytes)
{
if (vcpu->mmio_read_completed) {
- memcpy(val, vcpu->mmio_data, bytes);
trace_kvm_mmio(KVM_TRACE_MMIO_READ, bytes,
- vcpu->mmio_phys_addr, *(u64 *)val);
+ vcpu->mmio_fragments[0].gpa, *(u64 *)val);
vcpu->mmio_read_completed = 0;
return 1;
}
@@ -3756,8 +3755,9 @@ static int read_exit_mmio(struct kvm_vcpu *vcpu, gpa_t gpa,
static int write_exit_mmio(struct kvm_vcpu *vcpu, gpa_t gpa,
void *val, int bytes)
{
- memcpy(vcpu->mmio_data, val, bytes);
- memcpy(vcpu->run->mmio.data, vcpu->mmio_data, 8);
+ struct kvm_mmio_fragment *frag = &vcpu->mmio_fragments[0];
+
+ memcpy(vcpu->run->mmio.data, frag->data, frag->len);
return X86EMUL_CONTINUE;
}
@@ -3784,10 +3784,7 @@ static int emulator_read_write_onepage(unsigned long addr, void *val,
gpa_t gpa;
int handled, ret;
bool write = ops->write;
-
- if (ops->read_write_prepare &&
- ops->read_write_prepare(vcpu, val, bytes))
- return X86EMUL_CONTINUE;
+ struct kvm_mmio_fragment *frag;
ret = vcpu_mmio_gva_to_gpa(vcpu, addr, &gpa, exception, write);
@@ -3813,15 +3810,19 @@ mmio:
bytes -= handled;
val += handled;
- vcpu->mmio_needed = 1;
- vcpu->run->exit_reason = KVM_EXIT_MMIO;
- vcpu->run->mmio.phys_addr = vcpu->mmio_phys_addr = gpa;
- vcpu->mmio_size = bytes;
- vcpu->run->mmio.len = min(vcpu->mmio_size, 8);
- vcpu->run->mmio.is_write = vcpu->mmio_is_write = write;
- vcpu->mmio_index = 0;
+ while (bytes) {
+ unsigned now = min(bytes, 8U);
- return ops->read_write_exit_mmio(vcpu, gpa, val, bytes);
+ frag = &vcpu->mmio_fragments[vcpu->mmio_nr_fragments++];
+ frag->gpa = gpa;
+ frag->data = val;
+ frag->len = now;
+
+ gpa += now;
+ val += now;
+ bytes -= now;
+ }
+ return X86EMUL_CONTINUE;
}
int emulator_read_write(struct x86_emulate_ctxt *ctxt, unsigned long addr,
@@ -3830,10 +3831,18 @@ int emulator_read_write(struct x86_emulate_ctxt *ctxt, unsigned long addr,
struct read_write_emulator_ops *ops)
{
struct kvm_vcpu *vcpu = emul_to_vcpu(ctxt);
+ gpa_t gpa;
+ int rc;
+
+ if (ops->read_write_prepare &&
+ ops->read_write_prepare(vcpu, val, bytes))
+ return X86EMUL_CONTINUE;
+
+ vcpu->mmio_nr_fragments = 0;
/* Crossing a page boundary? */
if (((addr + bytes - 1) ^ addr) & PAGE_MASK) {
- int rc, now;
+ int now;
now = -addr & ~PAGE_MASK;
rc = emulator_read_write_onepage(addr, val, now, exception,
@@ -3846,8 +3855,25 @@ int emulator_read_write(struct x86_emulate_ctxt *ctxt, unsigned long addr,
bytes -= now;
}
- return emulator_read_write_onepage(addr, val, bytes, exception,
- vcpu, ops);
+ rc = emulator_read_write_onepage(addr, val, bytes, exception,
+ vcpu, ops);
+ if (rc != X86EMUL_CONTINUE)
+ return rc;
+
+ if (!vcpu->mmio_nr_fragments)
+ return rc;
+
+ gpa = vcpu->mmio_fragments[0].gpa;
+
+ vcpu->mmio_needed = 1;
+ vcpu->mmio_cur_fragment = 0;
+
+ vcpu->run->mmio.len = vcpu->mmio_fragments[0].len;
+ vcpu->run->mmio.is_write = vcpu->mmio_is_write = ops->write;
+ vcpu->run->exit_reason = KVM_EXIT_MMIO;
+ vcpu->run->mmio.phys_addr = gpa;
+
+ return ops->read_write_exit_mmio(vcpu, gpa, val, bytes);
}
static int emulator_read_emulated(struct x86_emulate_ctxt *ctxt,
@@ -5446,33 +5472,55 @@ static int __vcpu_run(struct kvm_vcpu *vcpu)
return r;
}
+/*
+ * Implements the following, as a state machine:
+ *
+ * read:
+ * for each fragment
+ * write gpa, len
+ * exit
+ * copy data
+ * execute insn
+ *
+ * write:
+ * for each fragment
+ * write gpa, len
+ * copy data
+ * exit
+ */
static int complete_mmio(struct kvm_vcpu *vcpu)
{
struct kvm_run *run = vcpu->run;
+ struct kvm_mmio_fragment *frag;
int r;
if (!(vcpu->arch.pio.count || vcpu->mmio_needed))
return 1;
if (vcpu->mmio_needed) {
- vcpu->mmio_needed = 0;
+ /* Complete previous fragment */
+ frag = &vcpu->mmio_fragments[vcpu->mmio_cur_fragment++];
if (!vcpu->mmio_is_write)
- memcpy(vcpu->mmio_data + vcpu->mmio_index,
- run->mmio.data, 8);
- vcpu->mmio_index += 8;
- if (vcpu->mmio_index < vcpu->mmio_size) {
- run->exit_reason = KVM_EXIT_MMIO;
- run->mmio.phys_addr = vcpu->mmio_phys_addr + vcpu->mmio_index;
- memcpy(run->mmio.data, vcpu->mmio_data + vcpu->mmio_index, 8);
- run->mmio.len = min(vcpu->mmio_size - vcpu->mmio_index, 8);
- run->mmio.is_write = vcpu->mmio_is_write;
- vcpu->mmio_needed = 1;
- return 0;
+ memcpy(frag->data, run->mmio.data, frag->len);
+ if (vcpu->mmio_cur_fragment == vcpu->mmio_nr_fragments) {
+ vcpu->mmio_needed = 0;
+ if (vcpu->mmio_is_write)
+ return 1;
+ vcpu->mmio_read_completed = 1;
+ goto done;
}
+ /* Initiate next fragment */
+ ++frag;
+ run->exit_reason = KVM_EXIT_MMIO;
+ run->mmio.phys_addr = frag->gpa;
if (vcpu->mmio_is_write)
- return 1;
- vcpu->mmio_read_completed = 1;
+ memcpy(run->mmio.data, frag->data, frag->len);
+ run->mmio.len = frag->len;
+ run->mmio.is_write = vcpu->mmio_is_write;
+ return 0;
+
}
+done:
vcpu->srcu_idx = srcu_read_lock(&vcpu->kvm->srcu);
r = emulate_instruction(vcpu, EMULTYPE_NO_DECODE);
srcu_read_unlock(&vcpu->kvm->srcu, vcpu->srcu_idx);
diff --git a/include/linux/kvm_host.h b/include/linux/kvm_host.h
index a2d00b1bbf54..186ffab0b9f0 100644
--- a/include/linux/kvm_host.h
+++ b/include/linux/kvm_host.h
@@ -35,6 +35,20 @@
#endif
/*
+ * If we support unaligned MMIO, at most one fragment will be split into two:
+ */
+#ifdef KVM_UNALIGNED_MMIO
+# define KVM_EXTRA_MMIO_FRAGMENTS 1
+#else
+# define KVM_EXTRA_MMIO_FRAGMENTS 0
+#endif
+
+#define KVM_USER_MMIO_SIZE 8
+
+#define KVM_MAX_MMIO_FRAGMENTS \
+ (KVM_MMIO_SIZE / KVM_USER_MMIO_SIZE + KVM_EXTRA_MMIO_FRAGMENTS)
+
+/*
* vcpu->requests bit members
*/
#define KVM_REQ_TLB_FLUSH 0
@@ -117,6 +131,16 @@ enum {
EXITING_GUEST_MODE
};
+/*
+ * Sometimes a large or cross-page mmio needs to be broken up into separate
+ * exits for userspace servicing.
+ */
+struct kvm_mmio_fragment {
+ gpa_t gpa;
+ void *data;
+ unsigned len;
+};
+
struct kvm_vcpu {
struct kvm *kvm;
#ifdef CONFIG_PREEMPT_NOTIFIERS
@@ -144,10 +168,9 @@ struct kvm_vcpu {
int mmio_needed;
int mmio_read_completed;
int mmio_is_write;
- int mmio_size;
- int mmio_index;
- unsigned char mmio_data[KVM_MMIO_SIZE];
- gpa_t mmio_phys_addr;
+ int mmio_cur_fragment;
+ int mmio_nr_fragments;
+ struct kvm_mmio_fragment mmio_fragments[KVM_MAX_MMIO_FRAGMENTS];
#endif
#ifdef CONFIG_KVM_ASYNC_PF
generated by cgit v1.2.3 (git 2.39.1) at 2024-11-18 08:14:13 +0000