This patch converts hw/vesa.c to use guest-mapped memory for framebuffer and
drops the slow MMIO emulation. This speeds up framebuffer accesses
considerably. Please note that this can be optimized even more with the
KVM_GET_DIRTY_LOG ioctl() as explained by Alexander Graf.
Cc: Alexander Graf <agraf@xxxxxxx>
Cc: Cyrill Gorcunov <gorcunov@xxxxxxxxx>
Cc: Ingo Molnar <mingo@xxxxxxx>
Cc: John Floren <john@xxxxxxxxxxx>
Cc: Sasha Levin <levinsasha928@xxxxxxxxx>
Signed-off-by: Pekka Enberg <penberg@xxxxxxxxxx>
---
tools/kvm/hw/vesa.c | 17 +++++------------
tools/kvm/include/kvm/kvm.h | 1 +
tools/kvm/kvm.c | 8 ++++----
3 files changed, 10 insertions(+), 16 deletions(-)
diff --git a/tools/kvm/hw/vesa.c b/tools/kvm/hw/vesa.c
index 48d31ce..be9c109 100644
--- a/tools/kvm/hw/vesa.c
+++ b/tools/kvm/hw/vesa.c
@@ -8,6 +8,7 @@
#include "kvm/irq.h"
#include "kvm/kvm.h"
#include "kvm/pci.h"
+#include <sys/mman.h>
#include <sys/types.h>
#include <sys/ioctl.h>
@@ -40,14 +41,6 @@ static struct pci_device_header vesa_pci_device = {
.bar[1] = VESA_MEM_ADDR | PCI_BASE_ADDRESS_SPACE_MEMORY,
};
-static void vesa_mmio_callback(u64 addr, u8 *data, u32 len, u8 is_write)
-{
- if (!is_write)
- return;
-
- fb__write(addr, data, len);
-}
-
static struct framebuffer vesafb;
struct framebuffer *vesa__init(struct kvm *kvm)
@@ -65,12 +58,12 @@ struct framebuffer *vesa__init(struct kvm *kvm)
vesa_pci_device.bar[0] = vesa_base_addr | PCI_BASE_ADDRESS_SPACE_IO;
pci__register(&vesa_pci_device, dev);
- kvm__register_mmio(kvm, VESA_MEM_ADDR, VESA_MEM_SIZE, &vesa_mmio_callback);
-
- mem = calloc(1, VESA_MEM_SIZE);
- if (!mem)
+ mem = mmap(NULL, VESA_MEM_SIZE, PROT_RW, MAP_ANON_NORESERVE, -1, 0);
+ if (mem == MAP_FAILED)
return NULL;
+ kvm__register_mem_slot(kvm, 1, VESA_MEM_ADDR, VESA_MEM_SIZE, mem);
+
vesafb = (struct framebuffer) {
.width = VESA_WIDTH,
.height = VESA_HEIGHT,
diff --git a/tools/kvm/include/kvm/kvm.h b/tools/kvm/include/kvm/kvm.h
index 55551de..0628402 100644
--- a/tools/kvm/include/kvm/kvm.h
+++ b/tools/kvm/include/kvm/kvm.h
@@ -49,6 +49,7 @@ void kvm__stop_timer(struct kvm *kvm);
void kvm__irq_line(struct kvm *kvm, int irq, int level);
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_slot(struct kvm *kvm, u32 slot, 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));
bool kvm__deregister_mmio(struct kvm *kvm, u64 phys_addr);
void kvm__pause(void);
diff --git a/tools/kvm/kvm.c b/tools/kvm/kvm.c
index 54e3203..de642c7 100644
--- a/tools/kvm/kvm.c
+++ b/tools/kvm/kvm.c
@@ -162,7 +162,7 @@ static bool kvm__cpu_supports_vm(void)
return regs.ecx & (1 << feature);
}
-static void kvm_register_mem_slot(struct kvm *kvm, u32 slot, u64 guest_phys, u64 size, void *userspace_addr)
+void kvm__register_mem_slot(struct kvm *kvm, u32 slot, u64 guest_phys, u64 size, void *userspace_addr)
{
struct kvm_userspace_memory_region mem;
int ret;
@@ -200,7 +200,7 @@ void kvm__init_ram(struct kvm *kvm)
phys_size = kvm->ram_size;
host_mem = kvm->ram_start;
- kvm_register_mem_slot(kvm, 0, phys_start, phys_size, host_mem);
+ kvm__register_mem_slot(kvm, 0, phys_start, phys_size, host_mem);
} else {
/* First RAM range from zero to the PCI gap: */
@@ -208,7 +208,7 @@ void kvm__init_ram(struct kvm *kvm)
phys_size = KVM_32BIT_GAP_START;
host_mem = kvm->ram_start;
- kvm_register_mem_slot(kvm, 0, phys_start, phys_size, host_mem);
+ kvm__register_mem_slot(kvm, 0, phys_start, phys_size, host_mem);
/* Second RAM range from 4GB to the end of RAM: */
@@ -216,7 +216,7 @@ void kvm__init_ram(struct kvm *kvm)
phys_size = kvm->ram_size - phys_size;
host_mem = kvm->ram_start + phys_start;
- kvm_register_mem_slot(kvm, 1, phys_start, phys_size, host_mem);
+ kvm__register_mem_slot(kvm, 1, phys_start, phys_size, host_mem);
}
}
--
1.7.0.4
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