Coalescing MMIOs is only required when we really want avoid having to exit
to userspace for every MMIO write, usually it's not the case so no reason
to coalesce every MMIO zone (I was also pretty sure it didn't always coalesce
zones)..
Signed-off-by: Sasha Levin <levinsasha928@xxxxxxxxx>
---
tools/kvm/hw/pci-shmem.c | 2 +-
tools/kvm/include/kvm/kvm.h | 4 +++-
tools/kvm/mmio.c | 23 +++++++++++++----------
tools/kvm/virtio/pci.c | 2 +-
4 files changed, 18 insertions(+), 13 deletions(-)
diff --git a/tools/kvm/hw/pci-shmem.c b/tools/kvm/hw/pci-shmem.c
index fd954c5..6130131 100644
--- a/tools/kvm/hw/pci-shmem.c
+++ b/tools/kvm/hw/pci-shmem.c
@@ -233,7 +233,7 @@ int pci_shmem__init(struct kvm *kvm)
/* Register MMIO space for MSI-X */
ivshmem_registers = ioport__register(IOPORT_EMPTY, &shmem_pci__io_ops, IOPORT_SIZE, NULL);
msix_block = pci_get_io_space_block(0x1010);
- kvm__register_mmio(kvm, msix_block, 0x1010, callback_mmio_msix, NULL);
+ kvm__register_mmio(kvm, msix_block, 0x1010, false, callback_mmio_msix, NULL);
/*
* This registers 3 BARs:
diff --git a/tools/kvm/include/kvm/kvm.h b/tools/kvm/include/kvm/kvm.h
index 7159952..0bec7a9 100644
--- a/tools/kvm/include/kvm/kvm.h
+++ b/tools/kvm/include/kvm/kvm.h
@@ -44,7 +44,9 @@ void kvm__irq_trigger(struct kvm *kvm, int irq);
bool kvm__emulate_io(struct kvm *kvm, u16 port, void *data, int direction, int size, u32 count);
bool kvm__emulate_mmio(struct kvm *kvm, u64 phys_addr, u8 *data, u32 len, u8 is_write);
void kvm__register_mem(struct kvm *kvm, u64 guest_phys, u64 size, void *userspace_addr);
-bool kvm__register_mmio(struct kvm *kvm, u64 phys_addr, u64 phys_addr_len, void (*kvm_mmio_callback_fn)(u64 addr, u8 *data, u32 len, u8 is_write, void *ptr), void *ptr);
+bool kvm__register_mmio(struct kvm *kvm, u64 phys_addr, u64 phys_addr_len, bool coalesce,
+ void (*mmio_fn)(u64 addr, u8 *data, u32 len, u8 is_write, void *ptr),
+ void *ptr);
bool kvm__deregister_mmio(struct kvm *kvm, u64 phys_addr);
void kvm__pause(void);
void kvm__continue(void);
diff --git a/tools/kvm/mmio.c b/tools/kvm/mmio.c
index de7320f..6e8d1bb 100644
--- a/tools/kvm/mmio.c
+++ b/tools/kvm/mmio.c
@@ -56,7 +56,9 @@ static const char *to_direction(u8 is_write)
return "read";
}
-bool kvm__register_mmio(struct kvm *kvm, u64 phys_addr, u64 phys_addr_len, void (*mmio_fn)(u64 addr, u8 *data, u32 len, u8 is_write, void *ptr), void *ptr)
+bool kvm__register_mmio(struct kvm *kvm, u64 phys_addr, u64 phys_addr_len, bool coalesce,
+ void (*mmio_fn)(u64 addr, u8 *data, u32 len, u8 is_write, void *ptr),
+ void *ptr)
{
struct mmio_mapping *mmio;
struct kvm_coalesced_mmio_zone zone;
@@ -72,16 +74,17 @@ bool kvm__register_mmio(struct kvm *kvm, u64 phys_addr, u64 phys_addr_len, void
.ptr = ptr,
};
- zone = (struct kvm_coalesced_mmio_zone) {
- .addr = phys_addr,
- .size = phys_addr_len,
- };
- ret = ioctl(kvm->vm_fd, KVM_REGISTER_COALESCED_MMIO, &zone);
- if (ret < 0) {
- free(mmio);
- return false;
+ if (coalesce) {
+ zone = (struct kvm_coalesced_mmio_zone) {
+ .addr = phys_addr,
+ .size = phys_addr_len,
+ };
+ ret = ioctl(kvm->vm_fd, KVM_REGISTER_COALESCED_MMIO, &zone);
+ if (ret < 0) {
+ free(mmio);
+ return false;
+ }
}
-
br_write_lock();
ret = mmio_insert(&mmio_tree, mmio);
br_write_unlock();
diff --git a/tools/kvm/virtio/pci.c b/tools/kvm/virtio/pci.c
index a7da8e8..2ffa5de 100644
--- a/tools/kvm/virtio/pci.c
+++ b/tools/kvm/virtio/pci.c
@@ -290,7 +290,7 @@ int virtio_pci__init(struct kvm *kvm, struct virtio_trans *vtrans, void *dev,
vpci->msix_io_block = pci_get_io_space_block(PCI_IO_SIZE * 2);
vpci->base_addr = ioport__register(IOPORT_EMPTY, &virtio_pci__io_ops, IOPORT_SIZE, vtrans);
- kvm__register_mmio(kvm, vpci->msix_io_block, PCI_IO_SIZE, callback_mmio_table, vpci);
+ kvm__register_mmio(kvm, vpci->msix_io_block, PCI_IO_SIZE, false, callback_mmio_table, vpci);
vpci->pci_hdr = (struct pci_device_header) {
.vendor_id = cpu_to_le16(PCI_VENDOR_ID_REDHAT_QUMRANET),
--
1.7.8
--
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