Re: [uq/master patch 2/5] kvm: add logging count to slots

Jan Kiszka
2010-04-24T07:35:05Z

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Marcelo Tosatti wrote:
> Otherwise there is no way to differentiate between global and slot
> specific logging, so for example
>
> vga dirty log start
> migration start
> migration fail
>
> Disables dirty logging for the vga slot.

This is not true (unless there is a bug): Migration logging is tracked
via KVMState::migration_log and vga logging via KVMSlot::flags. Both are
merged in kvm_set_user_memory_region. Thus no such change is required
for upstream.

Jan

>
> Signed-off-by: Marcelo Tosatti <mtosatti@redhat.com>
>
> Index: qemu-kvm/kvm-all.c
> ===================================================================
> --- qemu-kvm.orig/kvm-all.c
> +++ qemu-kvm/kvm-all.c
> @@ -47,6 +47,7 @@ typedef struct KVMSlot
> ram_addr_t phys_offset;
> int slot;
> int flags;
> + int logging_count;
> } KVMSlot;
>
> typedef struct kvm_dirty_log KVMDirtyLog;
> @@ -218,20 +219,11 @@ err:
> /*
> * dirty pages logging control
> */
> -static int kvm_dirty_pages_log_change(target_phys_addr_t phys_addr,
> - ram_addr_t size, int flags, int mask)
> +static int kvm_dirty_pages_log_change(KVMSlot *mem, int flags, int mask)
> {
> KVMState *s = kvm_state;
> - KVMSlot *mem = kvm_lookup_matching_slot(s, phys_addr, phys_addr + size);
> int old_flags;
>
> - if (mem == NULL) {
> - fprintf(stderr, "BUG: %s: invalid parameters " TARGET_FMT_plx "-"
> - TARGET_FMT_plx "\n", __func__, phys_addr,
> - (target_phys_addr_t)(phys_addr + size - 1));
> - return -EINVAL;
> - }
> -
> old_flags = mem->flags;
>
> flags = (mem->flags & ~mask) | flags;
> @@ -250,16 +242,42 @@ static int kvm_dirty_pages_log_change(ta
>
> int kvm_log_start(target_phys_addr_t phys_addr, ram_addr_t size)
> {
> - return kvm_dirty_pages_log_change(phys_addr, size,
> - KVM_MEM_LOG_DIRTY_PAGES,
> - KVM_MEM_LOG_DIRTY_PAGES);
> + KVMState *s = kvm_state;
> + KVMSlot *mem = kvm_lookup_matching_slot(s, phys_addr, phys_addr + size);
> +
> + if (mem == NULL) {
> + fprintf(stderr, "BUG: %s: invalid parameters " TARGET_FMT_plx "-"
> + TARGET_FMT_plx "\n", __func__, phys_addr,
> + (target_phys_addr_t)(phys_addr + size - 1));
> + return -EINVAL;
> + }
> +
> + if (mem->logging_count++)
> + return 0;
> +
> + return kvm_dirty_pages_log_change(mem,
> + KVM_MEM_LOG_DIRTY_PAGES,
> + KVM_MEM_LOG_DIRTY_PAGES);
> }
>
> int kvm_log_stop(target_phys_addr_t phys_addr, ram_addr_t size)
> {
> - return kvm_dirty_pages_log_change(phys_addr, size,
> - 0,
> - KVM_MEM_LOG_DIRTY_PAGES);
> + KVMState *s = kvm_state;
> + KVMSlot *mem = kvm_lookup_matching_slot(s, phys_addr, phys_addr + size);
> +
> + if (mem == NULL) {
> + fprintf(stderr, "BUG: %s: invalid parameters " TARGET_FMT_plx "-"
> + TARGET_FMT_plx "\n", __func__, phys_addr,
> + (target_phys_addr_t)(phys_addr + size - 1));
> + return -EINVAL;
> + }
> +
> + if (--mem->logging_count)
> + return 0;
> +
> + return kvm_dirty_pages_log_change(mem,
> + 0,
> + KVM_MEM_LOG_DIRTY_PAGES);
> }
>
> static int kvm_set_migration_log(int enable)
> @@ -273,12 +291,15 @@ static int kvm_set_migration_log(int ena
> for (i = 0; i < ARRAY_SIZE(s->slots); i++) {
> mem = &s->slots[i];
>
> - if (!!(mem->flags & KVM_MEM_LOG_DIRTY_PAGES) == enable) {
> - continue;
> - }
> - err = kvm_set_user_memory_region(s, mem);
> - if (err) {
> - return err;
> + if (mem->memory_size) {
> + if (enable) {
> + err = kvm_log_start(mem->start_addr, mem->memory_size);
> + } else {
> + err = kvm_log_stop(mem->start_addr, mem->memory_size);
> + }
> + if (err) {
> + return err;
> + }
> }
> }
> return 0;
> @@ -442,6 +463,7 @@ static void kvm_set_phys_mem(target_phys
>
> /* unregister the overlapping slot */
> mem->memory_size = 0;
> + mem->logging_count = 0;
> err = kvm_set_user_memory_region(s, mem);
> if (err) {
> fprintf(stderr, "%s: error unregistering overlapping slot: %s\n",
>
>
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