| Message ID | 1430152117-100558-28-git-send-email-pbonzini@redhat.com |
|---|---|
| State | New |
| Headers | show |
On Mon, 04/27 18:28, Paolo Bonzini wrote: > From: Stefan Hajnoczi <stefanha@redhat.com> > > The cpu_physical_memory_reset_dirty() function is sometimes used > together with cpu_physical_memory_get_dirty(). This is not atomic since > two separate accesses to the dirty memory bitmap are made. > > Turn cpu_physical_memory_reset_dirty() and > cpu_physical_memory_clear_dirty_range_type() into the atomic > cpu_physical_memory_test_and_clear_dirty(). > > Signed-off-by: Stefan Hajnoczi <stefanha@redhat.com> > Message-Id: <1417519399-3166-6-git-send-email-stefanha@redhat.com> > Signed-off-by: Paolo Bonzini <pbonzini@redhat.com> > --- > cputlb.c | 4 ++-- > exec.c | 23 +++++++++++++++++------ > include/exec/ram_addr.h | 33 ++++++++++----------------------- > memory.c | 11 ++++------- > 4 files changed, 33 insertions(+), 38 deletions(-) > > diff --git a/cputlb.c b/cputlb.c > index a86e76f..75b2dcf 100644 > --- a/cputlb.c > +++ b/cputlb.c > @@ -125,8 +125,8 @@ void tlb_flush_page(CPUState *cpu, target_ulong addr) > can be detected */ > void tlb_protect_code(ram_addr_t ram_addr) > { > - cpu_physical_memory_reset_dirty(ram_addr, TARGET_PAGE_SIZE, > - DIRTY_MEMORY_CODE); > + cpu_physical_memory_test_and_clear_dirty(ram_addr, TARGET_PAGE_SIZE, > + DIRTY_MEMORY_CODE); > } > > /* update the TLB so that writes in physical page 'phys_addr' are no longer > diff --git a/exec.c b/exec.c > index b7aebbf..daed5a7 100644 > --- a/exec.c > +++ b/exec.c > @@ -857,16 +857,27 @@ static void tlb_reset_dirty_range_all(ram_addr_t start, ram_addr_t length) > } > > /* Note: start and end must be within the same ram block. */ > -void cpu_physical_memory_reset_dirty(ram_addr_t start, ram_addr_t length, > - unsigned client) > +bool cpu_physical_memory_test_and_clear_dirty(ram_addr_t start, > + ram_addr_t length, > + unsigned client) > { > - if (length == 0) > - return; > - cpu_physical_memory_clear_dirty_range_type(start, length, client); > + unsigned long end, page; > + bool dirty; > + > + if (length == 0) { > + return false; > + } > > - if (tcg_enabled()) { > + end = TARGET_PAGE_ALIGN(start + length) >> TARGET_PAGE_BITS; > + page = start >> TARGET_PAGE_BITS; > + dirty = bitmap_test_and_clear_atomic(ram_list.dirty_memory[client], > + page, end - page); > + > + if (dirty && tcg_enabled()) { > tlb_reset_dirty_range_all(start, length); > } > + > + return dirty; > } > > /* Called from RCU critical section */ > diff --git a/include/exec/ram_addr.h b/include/exec/ram_addr.h > index 9bd7827..ea77187 100644 > --- a/include/exec/ram_addr.h > +++ b/include/exec/ram_addr.h > @@ -194,30 +194,19 @@ static inline void cpu_physical_memory_set_dirty_lebitmap(unsigned long *bitmap, > } > #endif /* not _WIN32 */ > > -static inline void cpu_physical_memory_clear_dirty_range_type(ram_addr_t start, > - ram_addr_t length, > - unsigned client) > -{ > - unsigned long end, page; > - > - assert(client < DIRTY_MEMORY_NUM); > - end = TARGET_PAGE_ALIGN(start + length) >> TARGET_PAGE_BITS; > - page = start >> TARGET_PAGE_BITS; > - bitmap_clear(ram_list.dirty_memory[client], page, end - page); > -} > +bool cpu_physical_memory_test_and_clear_dirty(ram_addr_t start, > + ram_addr_t length, > + unsigned client); > > static inline void cpu_physical_memory_clear_dirty_range(ram_addr_t start, > ram_addr_t length) > { > - cpu_physical_memory_clear_dirty_range_type(start, length, DIRTY_MEMORY_MIGRATION); > - cpu_physical_memory_clear_dirty_range_type(start, length, DIRTY_MEMORY_VGA); > - cpu_physical_memory_clear_dirty_range_type(start, length, DIRTY_MEMORY_CODE); > + cpu_physical_memory_test_and_clear_dirty(start, length, DIRTY_MEMORY_MIGRATION); Is this line too long? Otherwise, Reviewed-by: Fam Zheng <famz@redhat.com> > + cpu_physical_memory_test_and_clear_dirty(start, length, DIRTY_MEMORY_VGA); > + cpu_physical_memory_test_and_clear_dirty(start, length, DIRTY_MEMORY_CODE); > } > > > -void cpu_physical_memory_reset_dirty(ram_addr_t start, ram_addr_t length, > - unsigned client); > - > static inline > uint64_t cpu_physical_memory_sync_dirty_bitmap(unsigned long *dest, > ram_addr_t start, > @@ -245,12 +234,10 @@ uint64_t cpu_physical_memory_sync_dirty_bitmap(unsigned long *dest, > } > } else { > for (addr = 0; addr < length; addr += TARGET_PAGE_SIZE) { > - if (cpu_physical_memory_get_dirty(start + addr, > - TARGET_PAGE_SIZE, > - DIRTY_MEMORY_MIGRATION)) { > - cpu_physical_memory_reset_dirty(start + addr, > - TARGET_PAGE_SIZE, > - DIRTY_MEMORY_MIGRATION); > + if (cpu_physical_memory_test_and_clear_dirty( > + start + addr, > + TARGET_PAGE_SIZE, > + DIRTY_MEMORY_MIGRATION)) { > long k = (start + addr) >> TARGET_PAGE_BITS; > if (!test_and_set_bit(k, dest)) { > num_dirty++; > diff --git a/memory.c b/memory.c > index 7422790..bb86b4b 100644 > --- a/memory.c > +++ b/memory.c > @@ -1397,13 +1397,9 @@ void memory_region_set_dirty(MemoryRegion *mr, hwaddr addr, > bool memory_region_test_and_clear_dirty(MemoryRegion *mr, hwaddr addr, > hwaddr size, unsigned client) > { > - bool ret; > assert(mr->terminates); > - ret = cpu_physical_memory_get_dirty(mr->ram_addr + addr, size, client); > - if (ret) { > - cpu_physical_memory_reset_dirty(mr->ram_addr + addr, size, client); > - } > - return ret; > + return cpu_physical_memory_test_and_clear_dirty(mr->ram_addr + addr, > + size, client); > } > > > @@ -1447,7 +1443,8 @@ void memory_region_reset_dirty(MemoryRegion *mr, hwaddr addr, > hwaddr size, unsigned client) > { > assert(mr->terminates); > - cpu_physical_memory_reset_dirty(mr->ram_addr + addr, size, client); > + cpu_physical_memory_test_and_clear_dirty(mr->ram_addr + addr, size, > + client); > } > > int memory_region_get_fd(MemoryRegion *mr) > -- > 1.8.3.1 > > >
On 26/05/2015 14:42, Fam Zheng wrote: >> > { >> > - cpu_physical_memory_clear_dirty_range_type(start, length, DIRTY_MEMORY_MIGRATION); >> > - cpu_physical_memory_clear_dirty_range_type(start, length, DIRTY_MEMORY_VGA); >> > - cpu_physical_memory_clear_dirty_range_type(start, length, DIRTY_MEMORY_CODE); >> > + cpu_physical_memory_test_and_clear_dirty(start, length, DIRTY_MEMORY_MIGRATION); > Is this line too long? Otherwise, Yes, it's 84 characters long. On the other hand, it is shorter than the existing line... Paolo > Reviewed-by: Fam Zheng <famz@redhat.com> > >> > + cpu_physical_memory_test_and_clear_dirty(start, length, DIRTY_MEMORY_VGA); >> > + cpu_physical_memory_test_and_clear_dirty(start, length, DIRTY_MEMORY_CODE); >> > } >> >
diff --git a/cputlb.c b/cputlb.c index a86e76f..75b2dcf 100644 --- a/cputlb.c +++ b/cputlb.c @@ -125,8 +125,8 @@ void tlb_flush_page(CPUState *cpu, target_ulong addr) can be detected */ void tlb_protect_code(ram_addr_t ram_addr) { - cpu_physical_memory_reset_dirty(ram_addr, TARGET_PAGE_SIZE, - DIRTY_MEMORY_CODE); + cpu_physical_memory_test_and_clear_dirty(ram_addr, TARGET_PAGE_SIZE, + DIRTY_MEMORY_CODE); } /* update the TLB so that writes in physical page 'phys_addr' are no longer diff --git a/exec.c b/exec.c index b7aebbf..daed5a7 100644 --- a/exec.c +++ b/exec.c @@ -857,16 +857,27 @@ static void tlb_reset_dirty_range_all(ram_addr_t start, ram_addr_t length) } /* Note: start and end must be within the same ram block. */ -void cpu_physical_memory_reset_dirty(ram_addr_t start, ram_addr_t length, - unsigned client) +bool cpu_physical_memory_test_and_clear_dirty(ram_addr_t start, + ram_addr_t length, + unsigned client) { - if (length == 0) - return; - cpu_physical_memory_clear_dirty_range_type(start, length, client); + unsigned long end, page; + bool dirty; + + if (length == 0) { + return false; + } - if (tcg_enabled()) { + end = TARGET_PAGE_ALIGN(start + length) >> TARGET_PAGE_BITS; + page = start >> TARGET_PAGE_BITS; + dirty = bitmap_test_and_clear_atomic(ram_list.dirty_memory[client], + page, end - page); + + if (dirty && tcg_enabled()) { tlb_reset_dirty_range_all(start, length); } + + return dirty; } /* Called from RCU critical section */ diff --git a/include/exec/ram_addr.h b/include/exec/ram_addr.h index 9bd7827..ea77187 100644 --- a/include/exec/ram_addr.h +++ b/include/exec/ram_addr.h @@ -194,30 +194,19 @@ static inline void cpu_physical_memory_set_dirty_lebitmap(unsigned long *bitmap, } #endif /* not _WIN32 */ -static inline void cpu_physical_memory_clear_dirty_range_type(ram_addr_t start, - ram_addr_t length, - unsigned client) -{ - unsigned long end, page; - - assert(client < DIRTY_MEMORY_NUM); - end = TARGET_PAGE_ALIGN(start + length) >> TARGET_PAGE_BITS; - page = start >> TARGET_PAGE_BITS; - bitmap_clear(ram_list.dirty_memory[client], page, end - page); -} +bool cpu_physical_memory_test_and_clear_dirty(ram_addr_t start, + ram_addr_t length, + unsigned client); static inline void cpu_physical_memory_clear_dirty_range(ram_addr_t start, ram_addr_t length) { - cpu_physical_memory_clear_dirty_range_type(start, length, DIRTY_MEMORY_MIGRATION); - cpu_physical_memory_clear_dirty_range_type(start, length, DIRTY_MEMORY_VGA); - cpu_physical_memory_clear_dirty_range_type(start, length, DIRTY_MEMORY_CODE); + cpu_physical_memory_test_and_clear_dirty(start, length, DIRTY_MEMORY_MIGRATION); + cpu_physical_memory_test_and_clear_dirty(start, length, DIRTY_MEMORY_VGA); + cpu_physical_memory_test_and_clear_dirty(start, length, DIRTY_MEMORY_CODE); } -void cpu_physical_memory_reset_dirty(ram_addr_t start, ram_addr_t length, - unsigned client); - static inline uint64_t cpu_physical_memory_sync_dirty_bitmap(unsigned long *dest, ram_addr_t start, @@ -245,12 +234,10 @@ uint64_t cpu_physical_memory_sync_dirty_bitmap(unsigned long *dest, } } else { for (addr = 0; addr < length; addr += TARGET_PAGE_SIZE) { - if (cpu_physical_memory_get_dirty(start + addr, - TARGET_PAGE_SIZE, - DIRTY_MEMORY_MIGRATION)) { - cpu_physical_memory_reset_dirty(start + addr, - TARGET_PAGE_SIZE, - DIRTY_MEMORY_MIGRATION); + if (cpu_physical_memory_test_and_clear_dirty( + start + addr, + TARGET_PAGE_SIZE, + DIRTY_MEMORY_MIGRATION)) { long k = (start + addr) >> TARGET_PAGE_BITS; if (!test_and_set_bit(k, dest)) { num_dirty++; diff --git a/memory.c b/memory.c index 7422790..bb86b4b 100644 --- a/memory.c +++ b/memory.c @@ -1397,13 +1397,9 @@ void memory_region_set_dirty(MemoryRegion *mr, hwaddr addr, bool memory_region_test_and_clear_dirty(MemoryRegion *mr, hwaddr addr, hwaddr size, unsigned client) { - bool ret; assert(mr->terminates); - ret = cpu_physical_memory_get_dirty(mr->ram_addr + addr, size, client); - if (ret) { - cpu_physical_memory_reset_dirty(mr->ram_addr + addr, size, client); - } - return ret; + return cpu_physical_memory_test_and_clear_dirty(mr->ram_addr + addr, + size, client); } @@ -1447,7 +1443,8 @@ void memory_region_reset_dirty(MemoryRegion *mr, hwaddr addr, hwaddr size, unsigned client) { assert(mr->terminates); - cpu_physical_memory_reset_dirty(mr->ram_addr + addr, size, client); + cpu_physical_memory_test_and_clear_dirty(mr->ram_addr + addr, size, + client); } int memory_region_get_fd(MemoryRegion *mr)