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[Qemu-devel] [PATCH, RESEND] kvm: Fix dirty tracking with large kernel p
From: |
David Gibson |
Subject: |
[Qemu-devel] [PATCH, RESEND] kvm: Fix dirty tracking with large kernel page size |
Date: |
Wed, 4 Apr 2012 11:15:54 +1000 |
If the kernel page size is larger than TARGET_PAGE_SIZE, which
happens for example on ppc64 with kernels compiled for 64K pages,
the dirty tracking doesn't work.
Cc: Avi Kivity <address@hidden>
Cc: Marcelo Tosatti <address@hidden>
Signed-off-by: Benjamin Herrenschmidt <address@hidden>
Signed-off-by: David Gibson <address@hidden>
---
kvm-all.c | 14 ++++++++++++--
1 files changed, 12 insertions(+), 2 deletions(-)
Please apply.
Changes since last post:
* Added assertion and comment in kvm_init() as requested by Jan Kiszka
diff --git a/kvm-all.c b/kvm-all.c
index ba2cee1..1f49d0a 100644
--- a/kvm-all.c
+++ b/kvm-all.c
@@ -354,6 +354,7 @@ static int
kvm_get_dirty_pages_log_range(MemoryRegionSection *section,
unsigned long page_number, c;
target_phys_addr_t addr, addr1;
unsigned int len = ((section->size / TARGET_PAGE_SIZE) + HOST_LONG_BITS -
1) / HOST_LONG_BITS;
+ unsigned long hpratio = getpagesize() / TARGET_PAGE_SIZE;
/*
* bitmap-traveling is faster than memory-traveling (for addr...)
@@ -365,10 +366,11 @@ static int
kvm_get_dirty_pages_log_range(MemoryRegionSection *section,
do {
j = ffsl(c) - 1;
c &= ~(1ul << j);
- page_number = i * HOST_LONG_BITS + j;
+ page_number = (i * HOST_LONG_BITS + j) * hpratio;
addr1 = page_number * TARGET_PAGE_SIZE;
addr = section->offset_within_region + addr1;
- memory_region_set_dirty(section->mr, addr, TARGET_PAGE_SIZE);
+ memory_region_set_dirty(section->mr, addr,
+ TARGET_PAGE_SIZE * hpratio);
} while (c != 0);
}
}
@@ -986,6 +988,14 @@ int kvm_init(void)
s = g_malloc0(sizeof(KVMState));
+ /*
+ * On systems where the kernel can support different base page
+ * sizes, host page size may be different from TARGET_PAGE_SIZE,
+ * even with KVM. TARGET_PAGE_SIZE is assumed to be the minimum
+ * page size for the system though.
+ */
+ assert(TARGET_PAGE_SIZE <= getpagesize());
+
#ifdef KVM_CAP_SET_GUEST_DEBUG
QTAILQ_INIT(&s->kvm_sw_breakpoints);
#endif
--
1.7.9.1
- [Qemu-devel] [PATCH, RESEND] kvm: Fix dirty tracking with large kernel page size,
David Gibson <=