[PATCH v2 5/6] kvm: add PV MMIO

Michael S. Tsirkin
2013-04-04T11:39:17Z

Add an option for users to specify PV eventfd
listeners, and utilize KVM's PV MMIO underneath.
Upodate all callers.

Signed-off-by: Michael S. Tsirkin <mst@redhat.com>
---
hw/dataplane/hostmem.c | 1 +
hw/ivshmem.c | 2 ++
hw/pci-testdev.c | 2 ++
hw/vhost.c | 4 ++--
hw/virtio-pci.c | 4 ++--
include/exec/memory.h | 10 ++++++++++
kvm-all.c | 15 ++++++++++++---
linux-headers/linux/kvm.h | 8 ++++++++
memory.c | 9 +++++++--
9 files changed, 46 insertions(+), 9 deletions(-)

diff --git a/hw/dataplane/hostmem.c b/hw/dataplane/hostmem.c
index 380537e..41d43e7 100644
--- a/hw/dataplane/hostmem.c
+++ b/hw/dataplane/hostmem.c
@@ -126,6 +126,7 @@ static void hostmem_listener_section_dummy(MemoryListener *listener,

static void hostmem_listener_eventfd_dummy(MemoryListener *listener,
MemoryRegionSection *section,
+ bool pv,
bool match_data, uint64_t data,
EventNotifier *e)
{
diff --git a/hw/ivshmem.c b/hw/ivshmem.c
index 68a2cf2..28e5978 100644
--- a/hw/ivshmem.c
+++ b/hw/ivshmem.c
@@ -352,6 +352,7 @@ static void ivshmem_add_eventfd(IVShmemState *s, int posn, int i)
memory_region_add_eventfd(&s->ivshmem_mmio,
DOORBELL,
4,
+ false,
true,
(posn << 16) | i,
&s->peers[posn].eventfds[i]);
@@ -362,6 +363,7 @@ static void ivshmem_del_eventfd(IVShmemState *s, int posn, int i)
memory_region_del_eventfd(&s->ivshmem_mmio,
DOORBELL,
4,
+ false,
true,
(posn << 16) | i,
&s->peers[posn].eventfds[i]);
diff --git a/hw/pci-testdev.c b/hw/pci-testdev.c
index 9486624..f0ebf99 100644
--- a/hw/pci-testdev.c
+++ b/hw/pci-testdev.c
@@ -80,6 +80,7 @@ static int pci_testdev_start(IOTest *test)
memory_region_add_eventfd(test->mr,
le32_to_cpu(test->hdr->offset),
test->size,
+ false,
test->match_data,
test->hdr->data,
&test->notifier);
@@ -94,6 +95,7 @@ static void pci_testdev_stop(IOTest *test)
memory_region_del_eventfd(test->mr,
le32_to_cpu(test->hdr->offset),
test->size,
+ false,
test->match_data,
test->hdr->data,
&test->notifier);
diff --git a/hw/vhost.c b/hw/vhost.c
index 4d6aee3..9ad7101 100644
--- a/hw/vhost.c
+++ b/hw/vhost.c
@@ -750,13 +750,13 @@ static void vhost_virtqueue_stop(struct vhost_dev *dev,
}

static void vhost_eventfd_add(MemoryListener *listener,
- MemoryRegionSection *section,
+ MemoryRegionSection *section, bool pv,
bool match_data, uint64_t data, EventNotifier *e)
{
}

static void vhost_eventfd_del(MemoryListener *listener,
- MemoryRegionSection *section,
+ MemoryRegionSection *section, bool pv,
bool match_data, uint64_t data, EventNotifier *e)
{
}
diff --git a/hw/virtio-pci.c b/hw/virtio-pci.c
index 19965e5..f9ff994 100644
--- a/hw/virtio-pci.c
+++ b/hw/virtio-pci.c
@@ -189,10 +189,10 @@ static int virtio_pci_set_host_notifier_internal(VirtIOPCIProxy *proxy,
}
virtio_queue_set_host_notifier_fd_handler(vq, true, set_handler);
memory_region_add_eventfd(&proxy->bar, VIRTIO_PCI_QUEUE_NOTIFY, 2,
- true, n, notifier);
+ false, true, n, notifier);
} else {
memory_region_del_eventfd(&proxy->bar, VIRTIO_PCI_QUEUE_NOTIFY, 2,
- true, n, notifier);
+ false, true, n, notifier);
virtio_queue_set_host_notifier_fd_handler(vq, false, false);
event_notifier_cleanup(notifier);
}
diff --git a/include/exec/memory.h b/include/exec/memory.h
index 2322732..3612004 100644
--- a/include/exec/memory.h
+++ b/include/exec/memory.h
@@ -215,8 +215,10 @@ struct MemoryListener {
void (*log_global_start)(MemoryListener *listener);
void (*log_global_stop)(MemoryListener *listener);
void (*eventfd_add)(MemoryListener *listener, MemoryRegionSection *section,
+ bool pv,
bool match_data, uint64_t data, EventNotifier *e);
void (*eventfd_del)(MemoryListener *listener, MemoryRegionSection *section,
+ bool pv,
bool match_data, uint64_t data, EventNotifier *e);
void (*coalesced_mmio_add)(MemoryListener *listener, MemoryRegionSection *section,
hwaddr addr, hwaddr len);
@@ -594,6 +596,9 @@ void memory_region_clear_flush_coalesced(MemoryRegion *mr);
* @mr: the memory region being updated.
* @addr: the address within @mr that is to be monitored
* @size: the size of the access to trigger the eventfd
+ * @pv: set if Guest can promise us that all accesses touching this address
+ * are writes of specified length, starting at the specified address.
+ * If not - it's a Guest bug. Might give faster access.
* @match_data: whether to match against @data, instead of just @addr
* @data: the data to match against the guest write
* @fd: the eventfd to be triggered when @addr, @size, and @data all match.
@@ -601,6 +606,7 @@ void memory_region_clear_flush_coalesced(MemoryRegion *mr);
void memory_region_add_eventfd(MemoryRegion *mr,
hwaddr addr,
unsigned size,
+ bool pv,
bool match_data,
uint64_t data,
EventNotifier *e);
@@ -614,6 +620,9 @@ void memory_region_add_eventfd(MemoryRegion *mr,
* @mr: the memory region being updated.
* @addr: the address within @mr that is to be monitored
* @size: the size of the access to trigger the eventfd
+ * @pv: set if Guest can promise us that all accesses touching this address
+ * are writes of specified length, starting at the specified address.
+ * If not - it's a Guest bug. Might give faster access.
* @match_data: whether to match against @data, instead of just @addr
* @data: the data to match against the guest write
* @fd: the eventfd to be triggered when @addr, @size, and @data all match.
@@ -621,6 +630,7 @@ void memory_region_add_eventfd(MemoryRegion *mr,
void memory_region_del_eventfd(MemoryRegion *mr,
hwaddr addr,
unsigned size,
+ bool pv,
bool match_data,
uint64_t data,
EventNotifier *e);
diff --git a/kvm-all.c b/kvm-all.c
index ce823f9..59835ca 100644
--- a/kvm-all.c
+++ b/kvm-all.c
@@ -500,7 +500,7 @@ int kvm_check_extension(KVMState *s, unsigned int extension)
return ret;
}

-static int kvm_set_ioeventfd_mmio(int fd, uint32_t addr, uint32_t val,
+static int kvm_set_ioeventfd_mmio(int fd, uint32_t addr, uint32_t val, bool pv,
bool assign, uint32_t size, bool datamatch)
{
int ret;
@@ -518,6 +518,11 @@ static int kvm_set_ioeventfd_mmio(int fd, uint32_t addr, uint32_t val,

if (datamatch) {
iofd.flags |= KVM_IOEVENTFD_FLAG_DATAMATCH;
+ /* Kernel doesn't support data match with PV MMIO. */
+ pv = false;
+ }
+ if (pv) {
+ iofd.flags |= KVM_IOEVENTFD_FLAG_PV_MMIO;
}
if (!assign) {
iofd.flags |= KVM_IOEVENTFD_FLAG_DEASSIGN;
@@ -802,6 +807,7 @@ static void kvm_log_global_stop(struct MemoryListener *listener)

static void kvm_mem_ioeventfd_add(MemoryListener *listener,
MemoryRegionSection *section,
+ bool pv,
bool match_data, uint64_t data,
EventNotifier *e)
{
@@ -809,7 +815,7 @@ static void kvm_mem_ioeventfd_add(MemoryListener *listener,
int r;

r = kvm_set_ioeventfd_mmio(fd, section->offset_within_address_space,
- data, true, section->size, match_data);
+ data, pv, true, section->size, match_data);
if (r < 0) {
abort();
}
@@ -817,6 +823,7 @@ static void kvm_mem_ioeventfd_add(MemoryListener *listener,

static void kvm_mem_ioeventfd_del(MemoryListener *listener,
MemoryRegionSection *section,
+ bool pv,
bool match_data, uint64_t data,
EventNotifier *e)
{
@@ -824,7 +831,7 @@ static void kvm_mem_ioeventfd_del(MemoryListener *listener,
int r;

r = kvm_set_ioeventfd_mmio(fd, section->offset_within_address_space,
- data, false, section->size, match_data);
+ data, pv, false, section->size, match_data);
if (r < 0) {
abort();
}
@@ -832,6 +839,7 @@ static void kvm_mem_ioeventfd_del(MemoryListener *listener,

static void kvm_io_ioeventfd_add(MemoryListener *listener,
MemoryRegionSection *section,
+ bool pv,
bool match_data, uint64_t data,
EventNotifier *e)
{
@@ -847,6 +855,7 @@ static void kvm_io_ioeventfd_add(MemoryListener *listener,

static void kvm_io_ioeventfd_del(MemoryListener *listener,
MemoryRegionSection *section,
+ bool pv,
bool match_data, uint64_t data,
EventNotifier *e)

diff --git a/linux-headers/linux/kvm.h b/linux-headers/linux/kvm.h
index caca979..871cc0a 100644
--- a/linux-headers/linux/kvm.h
+++ b/linux-headers/linux/kvm.h
@@ -449,11 +449,19 @@ enum {
kvm_ioeventfd_flag_nr_datamatch,
kvm_ioeventfd_flag_nr_pio,
kvm_ioeventfd_flag_nr_deassign,
+ kvm_ioeventfd_flag_nr_pv_mmio,
kvm_ioeventfd_flag_nr_max,
};

#define KVM_IOEVENTFD_FLAG_DATAMATCH (1 << kvm_ioeventfd_flag_nr_datamatch)
#define KVM_IOEVENTFD_FLAG_PIO (1 << kvm_ioeventfd_flag_nr_pio)
+/*
+ * PV_MMIO - Guest can promise us that all accesses touching this address
+ * are writes of specified length, starting at the specified address.
+ * If not - it's a Guest bug.
+ * Can not be used together with either PIO or DATAMATCH.
+ */
+#define KVM_IOEVENTFD_FLAG_PV_MMIO (1 << kvm_ioeventfd_flag_nr_pv_mmio)
#define KVM_IOEVENTFD_FLAG_DEASSIGN (1 << kvm_ioeventfd_flag_nr_deassign)

#define KVM_IOEVENTFD_VALID_FLAG_MASK ((1 << kvm_ioeventfd_flag_nr_max) - 1)
diff --git a/memory.c b/memory.c
index 92a2196..5a64b3c 100644
--- a/memory.c
+++ b/memory.c
@@ -162,6 +162,7 @@ struct CoalescedMemoryRange {

struct MemoryRegionIoeventfd {
AddrRange addr;
+ bool pv;
bool match_data;
uint64_t data;
EventNotifier *e;
@@ -600,7 +601,7 @@ static void address_space_add_del_ioeventfds(AddressSpace *as,
.offset_within_address_space = int128_get64(fd->addr.start),
.size = int128_get64(fd->addr.size),
};
- MEMORY_LISTENER_CALL(eventfd_del, Forward, &section,
+ MEMORY_LISTENER_CALL(eventfd_del, Forward, &section, fd->pv,
fd->match_data, fd->data, fd->e);
++iold;
} else if (inew < fds_new_nb
@@ -613,7 +614,7 @@ static void address_space_add_del_ioeventfds(AddressSpace *as,
.offset_within_address_space = int128_get64(fd->addr.start),
.size = int128_get64(fd->addr.size),
};
- MEMORY_LISTENER_CALL(eventfd_add, Reverse, &section,
+ MEMORY_LISTENER_CALL(eventfd_add, Reverse, &section, fd->pv,
fd->match_data, fd->data, fd->e);
++inew;
} else {
@@ -1243,6 +1244,7 @@ void memory_region_clear_flush_coalesced(MemoryRegion *mr)
void memory_region_add_eventfd(MemoryRegion *mr,
hwaddr addr,
unsigned size,
+ bool pv,
bool match_data,
uint64_t data,
EventNotifier *e)
@@ -1250,6 +1252,7 @@ void memory_region_add_eventfd(MemoryRegion *mr,
MemoryRegionIoeventfd mrfd = {
.addr.start = int128_make64(addr),
.addr.size = int128_make64(size),
+ .pv = pv,
.match_data = match_data,
.data = data,
.e = e,
@@ -1276,6 +1279,7 @@ void memory_region_add_eventfd(MemoryRegion *mr,
void memory_region_del_eventfd(MemoryRegion *mr,
hwaddr addr,
unsigned size,
+ bool pv,
bool match_data,
uint64_t data,
EventNotifier *e)
@@ -1283,6 +1287,7 @@ void memory_region_del_eventfd(MemoryRegion *mr,
MemoryRegionIoeventfd mrfd = {
.addr.start = int128_make64(addr),
.addr.size = int128_make64(size),
+ .pv = pv,
.match_data = match_data,
.data = data,
.e = e,
--
MST