KVM: Don't require explicit indication of completion of mmio or pio
It is illegal not to return from a pio or mmio request without completing
it, as mmio or pio is an atomic operation. Therefore, we can simplify
the userspace interface by avoiding the completion indication.
Signed-off-by: Avi Kivity <avi@qumranet.com>
diff --git a/drivers/kvm/kvm_main.c b/drivers/kvm/kvm_main.c
index f267dbb..c8b8cfa 100644
--- a/drivers/kvm/kvm_main.c
+++ b/drivers/kvm/kvm_main.c
@@ -1237,8 +1237,10 @@
kvm_arch_ops->decache_regs(vcpu);
kvm_arch_ops->set_rflags(vcpu, emulate_ctxt.eflags);
- if (vcpu->mmio_is_write)
+ if (vcpu->mmio_is_write) {
+ vcpu->mmio_needed = 0;
return EMULATE_DO_MMIO;
+ }
return EMULATE_DONE;
}
@@ -1692,8 +1694,6 @@
vcpu->regs[VCPU_REGS_RSI] += delta;
}
- vcpu->run->io_completed = 0;
-
kvm_arch_ops->decache_regs(vcpu);
io->count -= io->cur_count;
@@ -1800,25 +1800,25 @@
/* re-sync apic's tpr */
vcpu->cr8 = kvm_run->cr8;
- if (kvm_run->io_completed) {
- if (vcpu->pio.cur_count) {
- r = complete_pio(vcpu);
- if (r)
- goto out;
- } else if (!vcpu->mmio_is_write) {
- memcpy(vcpu->mmio_data, kvm_run->mmio.data, 8);
- vcpu->mmio_read_completed = 1;
- vcpu->mmio_needed = 0;
- r = emulate_instruction(vcpu, kvm_run,
- vcpu->mmio_fault_cr2, 0);
- if (r == EMULATE_DO_MMIO) {
- /*
- * Read-modify-write. Back to userspace.
- */
- kvm_run->exit_reason = KVM_EXIT_MMIO;
- r = 0;
- goto out;
- }
+ if (vcpu->pio.cur_count) {
+ r = complete_pio(vcpu);
+ if (r)
+ goto out;
+ }
+
+ if (vcpu->mmio_needed) {
+ memcpy(vcpu->mmio_data, kvm_run->mmio.data, 8);
+ vcpu->mmio_read_completed = 1;
+ vcpu->mmio_needed = 0;
+ r = emulate_instruction(vcpu, kvm_run,
+ vcpu->mmio_fault_cr2, 0);
+ if (r == EMULATE_DO_MMIO) {
+ /*
+ * Read-modify-write. Back to userspace.
+ */
+ kvm_run->exit_reason = KVM_EXIT_MMIO;
+ r = 0;
+ goto out;
}
}
diff --git a/include/linux/kvm.h b/include/linux/kvm.h
index 07bf353..738c2f5 100644
--- a/include/linux/kvm.h
+++ b/include/linux/kvm.h
@@ -11,7 +11,7 @@
#include <asm/types.h>
#include <linux/ioctl.h>
-#define KVM_API_VERSION 10
+#define KVM_API_VERSION 11
/*
* Architectural interrupt line count, and the size of the bitmap needed
@@ -58,9 +58,8 @@
/* for KVM_RUN, returned by mmap(vcpu_fd, offset=0) */
struct kvm_run {
/* in */
- __u32 io_completed; /* mmio/pio request completed */
__u8 request_interrupt_window;
- __u8 padding1[3];
+ __u8 padding1[7];
/* out */
__u32 exit_reason;