Call into kvm to know whether we can madvise(MADV_DONTNEED) pages.

Signed-off-by: Marcelo Tosatti <[EMAIL PROTECTED]>

Index: kvm-userspace.balloon/libkvm/libkvm.c
===================================================================
--- kvm-userspace.balloon.orig/libkvm/libkvm.c
+++ kvm-userspace.balloon/libkvm/libkvm.c
@@ -840,6 +840,20 @@ int kvm_is_ready_for_interrupt_injection
        return run->ready_for_interrupt_injection;
 }
 
+int kvm_zap_single_gfn(kvm_context_t kvm, unsigned long gfn)
+{
+       int r = -1;
+
+#ifdef KVM_CAP_ZAP_GFN
+       r = ioctl(kvm->fd, KVM_CHECK_EXTENSION, KVM_CAP_ZAP_GFN);
+       if (r > 0)
+               r = ioctl(kvm->vm_fd, KVM_ZAP_GFN, &gfn);
+       else
+               r = -1;
+#endif
+       return r;
+}
+
 int kvm_run(kvm_context_t kvm, int vcpu)
 {
        int r;
Index: kvm-userspace.balloon/libkvm/libkvm.h
===================================================================
--- kvm-userspace.balloon.orig/libkvm/libkvm.h
+++ kvm-userspace.balloon/libkvm/libkvm.h
@@ -422,6 +422,7 @@ int kvm_get_dirty_pages_range(kvm_contex
                              unsigned long end_addr, void *buf, void*opaque,
                              int (*cb)(unsigned long start, unsigned long len,
                                        void*bitmap, void *opaque));
+int kvm_zap_single_gfn(kvm_context_t kvm, unsigned long gfn);
 
 /*!
  * \brief Create a memory alias
Index: kvm-userspace.balloon/qemu/hw/virtio-balloon.c
===================================================================
--- kvm-userspace.balloon.orig/qemu/hw/virtio-balloon.c
+++ kvm-userspace.balloon/qemu/hw/virtio-balloon.c
@@ -17,6 +17,7 @@
 #include "balloon.h"
 #include "sysemu.h"
 #include "console.h"
+#include "qemu-kvm.h"
 
 #include <sys/mman.h>
 
@@ -60,22 +61,21 @@ static void virtio_balloon_handle_output
        unsigned int wlen = 0;
 
        for (i = 0; i < elem.out_num; i++) {
-           int flags;
            uint32_t *pfns = elem.out_sg[i].iov_base;
            unsigned int n_pfns = elem.out_sg[i].iov_len / 4;
            int j;
 
            for (j = 0; j < n_pfns; j++) {
-               if (vq == s->dvq) /* deflate */
-                   flags = MADV_WILLNEED;
-               else /* inflate */
-                   flags = MADV_DONTNEED;
-
-#if 0
-               /* can't use this until we have mmu notifier support */
-               madvise(phys_ram_base + (pfns[j] << TARGET_PAGE_BITS),
-                       TARGET_PAGE_SIZE, flags);
-#endif
+               if (vq == s->dvq)
+                    /* deflate */
+                       madvise(phys_ram_base + (pfns[j] << TARGET_PAGE_BITS),
+                               TARGET_PAGE_SIZE, MADV_WILLNEED);
+               else { /* inflate */
+                       if (kvm_zap_gfn(pfns[j]) == 0)
+                               madvise(phys_ram_base +
+                                       (pfns[j] << TARGET_PAGE_BITS),
+                                       TARGET_PAGE_SIZE, MADV_DONTNEED);
+               }
            }
 
            wlen += elem.out_sg[i].iov_len;
Index: kvm-userspace.balloon/qemu/qemu-kvm.c
===================================================================
--- kvm-userspace.balloon.orig/qemu/qemu-kvm.c
+++ kvm-userspace.balloon/qemu/qemu-kvm.c
@@ -65,6 +65,11 @@ static void sig_ipi_handler(int n)
 {
 }
 
+int kvm_zap_gfn(unsigned long gfn)
+{
+       return kvm_zap_single_gfn(kvm_context, gfn);
+}
+
 void kvm_update_interrupt_request(CPUState *env)
 {
     if (env && vcpu && env != vcpu->env) {
Index: kvm-userspace.balloon/qemu/qemu-kvm.h
===================================================================
--- kvm-userspace.balloon.orig/qemu/qemu-kvm.h
+++ kvm-userspace.balloon/qemu/qemu-kvm.h
@@ -24,6 +24,7 @@ int kvm_qemu_init_env(CPUState *env);
 int kvm_qemu_check_extension(int ext);
 void kvm_apic_init(CPUState *env);
 int kvm_set_irq(int irq, int level);
+int kvm_zap_gfn(unsigned long gfn);
 
 int kvm_physical_memory_set_dirty_tracking(int enable);
 int kvm_update_dirty_pages_log(void);

-- 


-------------------------------------------------------------------------
This SF.net email is sponsored by: Microsoft
Defy all challenges. Microsoft(R) Visual Studio 2008.
http://clk.atdmt.com/MRT/go/vse0120000070mrt/direct/01/
_______________________________________________
kvm-devel mailing list
kvm-devel@lists.sourceforge.net
https://lists.sourceforge.net/lists/listinfo/kvm-devel

Reply via email to