Add QEMU support for the KVM balloon driver.
Memory hinting is performed via madvise().
Signed-off-by: Marcelo Tosatti <mtosatti@xxxxxxxxxx>
Index: kvm-userspace/libkvm/libkvm.c
===================================================================
--- kvm-userspace.orig/libkvm/libkvm.c
+++ kvm-userspace/libkvm/libkvm.c
@@ -886,6 +886,17 @@ int kvm_is_ready_for_interrupt_injection
return run->ready_for_interrupt_injection;
}
+int kvm_sync_shadow_with_user(kvm_context_t kvm)
+{
+ int r = 0;
+#ifdef KVM_CAP_SYNC_SHADOW_WITH_USER
+ r = ioctl(kvm->fd, KVM_CHECK_EXTENSION, KVM_CAP_SYNC_SHADOW_WITH_USER);
+ if (r > 0)
+ r = ioctl(kvm->vm_fd, KVM_SYNC_SHADOW_WITH_USER);
+#endif
+ return r;
+}
+
int kvm_run(kvm_context_t kvm, int vcpu)
{
int r;
Index: kvm-userspace/libkvm/libkvm.h
===================================================================
--- kvm-userspace.orig/libkvm/libkvm.h
+++ kvm-userspace/libkvm/libkvm.h
@@ -423,6 +423,8 @@ int kvm_get_dirty_pages_range(kvm_contex
int (*cb)(unsigned long start, unsigned long len,
void*bitmap, void *opaque));
+int kvm_sync_shadow_with_user(kvm_context_t kvm);
+
/*!
* \brief Create a memory alias
*
Index: kvm-userspace/qemu/Makefile.target
===================================================================
--- kvm-userspace.orig/qemu/Makefile.target
+++ kvm-userspace/qemu/Makefile.target
@@ -464,7 +464,7 @@ VL_OBJS += rtl8139.o
VL_OBJS+= hypercall.o
# virtio devices
-VL_OBJS += virtio.o virtio-net.o virtio-blk.o
+VL_OBJS += virtio.o virtio-net.o virtio-blk.o virtio-balloon.o
ifeq ($(TARGET_BASE_ARCH), i386)
# Hardware support
Index: kvm-userspace/qemu/hw/pc.c
===================================================================
--- kvm-userspace.orig/qemu/hw/pc.c
+++ kvm-userspace/qemu/hw/pc.c
@@ -1029,6 +1029,8 @@ static void pc_init1(ram_addr_t ram_size
}
}
+ virtio_balloon_init(pci_bus);
+
#define USE_HYPERCALL
#ifdef USE_HYPERCALL
pci_hypercall_init(pci_bus);
Index: kvm-userspace/qemu/hw/pc.h
===================================================================
--- kvm-userspace.orig/qemu/hw/pc.h
+++ kvm-userspace/qemu/hw/pc.h
@@ -155,4 +155,7 @@ void *virtio_blk_init(PCIBus *bus, uint1
void extboot_init(BlockDriverState *bs, int cmd);
+/* virtio-balloon.c */
+void *virtio_balloon_init(PCIBus *bus);
+
#endif
Index: kvm-userspace/qemu/hw/virtio-balloon.c
===================================================================
--- /dev/null
+++ kvm-userspace/qemu/hw/virtio-balloon.c
@@ -0,0 +1,103 @@
+#include "virtio.h"
+#include "pc.h"
+
+typedef struct VirtIOBalloon
+{
+ VirtIODevice vdev;
+} VirtIOBalloon;
+
+struct virtio_balloon_hdr
+{
+ uint8_t cmd;
+ uint8_t status;
+};
+
+struct virtio_balloon_config
+{
+ uint32_t target_nrpages;
+};
+
+VirtIOBalloon *virtio_balloon;
+
+extern int64_t ram_size;
+int64_t target_ramsize;
+
+#define VIRTIO_ID_BALLOON 3
+
+#define CMD_BALLOON_INFLATE 0x1
+#define CMD_BALLOON_DEFLATE 0x2
+
+static VirtIOBalloon *to_virtio_balloon(VirtIODevice *vdev)
+{
+ return (VirtIOBalloon *)vdev;
+}
+
+static void virtio_balloon_queue(VirtIODevice *vdev, VirtQueue *vq)
+{
+ VirtIOBalloon *n = to_virtio_balloon(vdev);
+ VirtQueueElement elem;
+
+ while (virtqueue_pop(vq, &elem)) {
+ int i, r;
+ size_t len = 0;
+ struct virtio_balloon_hdr *hdr;
+ void *data;
+
+ hdr = (void *)elem.in_sg[0].iov_base;
+ switch(hdr->cmd) {
+ case CMD_BALLOON_INFLATE:
+ case CMD_BALLOON_DEFLATE:
+ data = elem.in_sg[1].iov_base;
+ len = elem.in_sg[1].iov_len;
+
+ r = kvm_handle_ballooning_call(data, len);
+ hdr->status = (uint8_t) r;
+ break;
+ default:
+ fprintf(stderr, "unknown command %x\n",
+ hdr->cmd);
+ hdr->status = 1;
+ }
+ len += sizeof(struct virtio_balloon_hdr);
+ virtqueue_push(vq, &elem, len);
+ virtio_notify(vdev, vq);
+ }
+}
+
+static void virtio_balloon_update_config(VirtIODevice *vdev, uint8_t *config)
+{
+ struct virtio_balloon_config cfg;
+
+ cfg.target_nrpages = target_ramsize / TARGET_PAGE_SIZE;
+
+ memcpy(config, &cfg, sizeof(cfg));
+}
+
+void *virtio_balloon_init(PCIBus *bus)
+{
+ VirtIOBalloon *n;
+
+ /* XXX: pif=0x80? */
+ n = (VirtIOBalloon *)virtio_init_pci(bus, "virtio-kvm-balloon", 0x1AF4,
+ 0x1003, 0, VIRTIO_ID_BALLOON,
+ 0xff, 0x80, 0x00, 4,
+ sizeof(VirtIOBalloon));
+
+ virtio_add_queue(&n->vdev, 128, virtio_balloon_queue);
+ n->vdev.update_config = virtio_balloon_update_config;
+ target_ramsize = ram_size;
+ virtio_balloon = n;
+
+ return &n->vdev;
+}
+
+int balloon_update_target(int64_t target)
+{
+ VirtIODevice *vdev = &virtio_balloon->vdev;
+ target_ramsize = target;
+
+ vdev->update_config(vdev, vdev->config);
+ qemu_set_irq(vdev->pci_dev.irq[0], 1);
+
+ return 1;
+}
Index: kvm-userspace/qemu/migration.c
===================================================================
--- kvm-userspace.orig/qemu/migration.c
+++ kvm-userspace/qemu/migration.c
@@ -34,6 +34,7 @@
#endif
#include <sys/wait.h>
+#include <sys/mman.h>
#define MIN_FINALIZE_SIZE (200 << 10)
#define MAX_ITERATIONS 30
@@ -765,6 +766,9 @@ static void migrate_incoming_homogeneous
for (i=0; i<n; i++)
p[i] = v;
+
+ if (v == 0)
+ madvise(phys_ram_base + addr, TARGET_PAGE_SIZE, MADV_DONTNEED);
}
static int migrate_incoming_page(QEMUFile *f, uint32_t addr)
Index: kvm-userspace/qemu/monitor.c
===================================================================
--- kvm-userspace.orig/qemu/monitor.c
+++ kvm-userspace/qemu/monitor.c
@@ -1339,6 +1339,8 @@ static term_cmd_t term_cmds[] = {
"", "cancel the current VM migration" },
{ "migrate_set_speed", "s", do_migrate_set_speed,
"value", "set maximum speed (in bytes) for migrations" },
+ { "setmem", "s", do_setmemory, "value",
+ "set memory for the guest (in bytes)" },
{ NULL, NULL, },
};
Index: kvm-userspace/qemu/qemu-kvm.c
===================================================================
--- kvm-userspace.orig/qemu/qemu-kvm.c
+++ kvm-userspace/qemu/qemu-kvm.c
@@ -21,6 +21,7 @@ int kvm_irqchip = 1;
#include <libkvm.h>
#include <pthread.h>
#include <sys/utsname.h>
+#include <sys/mman.h>
extern void perror(const char *s);
@@ -513,7 +514,74 @@ static int kvm_shutdown(void *opaque, in
qemu_system_reset_request();
return 1;
}
-
+
+static int do_balloon_on_page(unsigned int gfn, int is_inflate)
+{
+ unsigned long addr = gfn * TARGET_PAGE_SIZE;
+ unsigned char *curr_addr = phys_ram_base + addr;
+ int r;
+ int advice = is_inflate ? MADV_DONTNEED : MADV_NORMAL;
+
+ r = madvise(curr_addr, TARGET_PAGE_SIZE, advice);
+
+ if (r < 0) {
+ perror("madvise");
+ fprintf(stderr, "%s: gfn=0x%x is_inflate=%d mlock/madvise: failed\n",
+ __FUNCTION__, gfn, is_inflate);
+ }
+ return r;
+}
+
+int kvm_handle_ballooning_call(void *data, size_t len)
+{
+ unsigned int gfn;
+ unsigned int *curr_pfn;
+ int is_inflate;
+ int req_npages, npages;
+ int i, r = 0, saved_r = 0;
+
+ curr_pfn = data;
+
+ req_npages = (int)*curr_pfn++;
+
+ npages = abs(req_npages);
+ is_inflate = (req_npages > 0);
+
+ if (is_inflate)
+ kvm_sync_shadow_with_user(kvm_context);
+
+ for (i = 0; i < npages; i++, curr_pfn++) {
+ gfn = *curr_pfn;
+
+ r = do_balloon_on_page(gfn, is_inflate);
+ if (r) {
+ printf("do_balloon_on_page FAILED, gfn=0x%x, is_inflate=%d\n",
+ gfn, is_inflate);
+ goto out_failed;
+ }
+ }
+
+ return r;
+
+out_failed:
+ npages = i;
+ curr_pfn = data;
+ curr_pfn++;
+ saved_r = r;
+
+ for (i = 0; i<npages; i++, curr_pfn++) {
+ gfn = *curr_pfn;
+
+ r = do_balloon_on_page(gfn, !is_inflate);
+ if (r) {
+ printf("do_balloon_on_page EH FAILED, gfn=0x%x, is_inflate=%d\n",
+ gfn, !is_inflate);
+ return r;
+ }
+ }
+ return saved_r;
+}
+
static struct kvm_callbacks qemu_kvm_ops = {
.debug = kvm_debug,
.inb = kvm_inb,
@@ -546,6 +614,31 @@ int kvm_qemu_init()
return 0;
}
+void do_setmemory(const char *value)
+{
+ int target_ramsize;
+ char *ptr;
+
+ target_ramsize = strtol(value, &ptr, 10);
+ switch (*ptr) {
+ case 'G': case 'g':
+ target_ramsize *= 1024;
+ case 'M': case 'm':
+ target_ramsize *= 1024;
+ case 'K': case 'k':
+ target_ramsize *= 1024;
+ default:
+ break;
+ }
+
+ if (target_ramsize > ram_size) {
+ term_printf("Invalid RAM size, maximum: %d\n", ram_size);
+ return;
+ }
+
+ balloon_update_target(target_ramsize);
+}
+
int kvm_qemu_create_context(void)
{
int r;
Index: kvm-userspace/qemu/qemu-kvm.h
===================================================================
--- kvm-userspace.orig/qemu/qemu-kvm.h
+++ kvm-userspace/qemu/qemu-kvm.h
@@ -39,6 +39,9 @@ void kvm_arch_post_kvm_run(void *opaque,
int kvm_arch_has_work(CPUState *env);
int kvm_arch_try_push_interrupts(void *opaque);
void kvm_arch_update_regs_for_sipi(CPUState *env);
+int kvm_handle_ballooning_call(void *data, size_t len);
+
+void do_setmemory(const char *value);
extern int kvm_allowed;
extern int kvm_irqchip;
Index: kvm-userspace/qemu/vl.c
===================================================================
--- kvm-userspace.orig/qemu/vl.c
+++ kvm-userspace/qemu/vl.c
@@ -7216,6 +7216,30 @@ static void ram_decompress_close(RamDeco
inflateEnd(&s->zstream);
}
+#ifdef USE_KVM
+extern int64_t target_ramsize; /* qemu/hw/virtio-balloon.c */
+static void balloon_save(QEMUFile *f, void *opaque)
+{
+ qemu_put_be64(f, target_ramsize);
+}
+
+static int balloon_load(QEMUFile *f, void *opaque, int version_id)
+{
+ int64_t target;
+
+ if (version_id != 1)
+ return -EINVAL;
+
+ target = qemu_get_be64(f);
+ if (!target)
+ return -EINVAL;
+
+ balloon_update_target(target);
+
+ return 0;
+}
+#endif
+
static void ram_save_live(QEMUFile *f, void *opaque)
{
target_ulong addr;
@@ -9378,6 +9402,9 @@ int main(int argc, char **argv)
register_savevm("timer", 0, 2, timer_save, timer_load, NULL);
register_savevm("ram", 0, 3, ram_save, ram_load, NULL);
+ if (kvm_allowed)
+ register_savevm("balloon", 0, 1, balloon_save, balloon_load, NULL);
+
init_ioports();
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