[PATCH v3 34/70] kvm/memory: Introduce the infrastructure to set the default shared/private value

Xiaoyao Li
2023-11-15T07:19:44Z

Introduce new flag RAM_DEFAULT_PRIVATE for RAMBlock. It's used to
indicate the default attribute, private or not.

Set the RAM range to private explicitly when it's default private.

Originated-from: Isaku Yamahata <isaku.yamahata@intel.com>
Signed-off-by: Xiaoyao Li <xiaoyao.li@intel.com>
---
accel/kvm/kvm-all.c | 10 ++++++++++
include/exec/memory.h | 6 ++++++
system/memory.c | 13 +++++++++++++
3 files changed, 29 insertions(+)

diff --git a/accel/kvm/kvm-all.c b/accel/kvm/kvm-all.c
index a92fff471b58..316690d113d0 100644
--- a/accel/kvm/kvm-all.c
+++ b/accel/kvm/kvm-all.c
@@ -1467,6 +1467,16 @@ static void kvm_set_phys_mem(KVMMemoryListener *kml,
strerror(-err));
abort();
}
+
+ if (memory_region_is_default_private(mr)) {
+ err = kvm_set_memory_attributes_private(start_addr, slot_size);
+ if (err) {
+ error_report("%s: failed to set memory attribute private: %s\n",
+ __func__, strerror(-err));
+ exit(1);
+ }
+ }
+
start_addr += slot_size;
ram_start_offset += slot_size;
ram += slot_size;
diff --git a/include/exec/memory.h b/include/exec/memory.h
index f780367ab1bd..bdc4b98efe70 100644
--- a/include/exec/memory.h
+++ b/include/exec/memory.h
@@ -246,6 +246,9 @@ typedef struct IOMMUTLBEvent {
/* RAM can be private that has kvm gmem backend */
#define RAM_GUEST_MEMFD (1 << 12)

+/* RAM is default private */
+#define RAM_DEFAULT_PRIVATE (1 << 13)
+
static inline void iommu_notifier_init(IOMMUNotifier *n, IOMMUNotify fn,
IOMMUNotifierFlag flags,
hwaddr start, hwaddr end,
@@ -1715,6 +1718,9 @@ bool memory_region_is_protected(MemoryRegion *mr);
*/
bool memory_region_has_guest_memfd(MemoryRegion *mr);

+void memory_region_set_default_private(MemoryRegion *mr);
+bool memory_region_is_default_private(MemoryRegion *mr);
+
/**
* memory_region_get_iommu: check whether a memory region is an iommu
*
diff --git a/system/memory.c b/system/memory.c
index 69741d91bbb7..b0c58232b6f7 100644
--- a/system/memory.c
+++ b/system/memory.c
@@ -1867,6 +1867,19 @@ bool memory_region_has_guest_memfd(MemoryRegion *mr)
return mr->ram_block && mr->ram_block->guest_memfd >= 0;
}

+bool memory_region_is_default_private(MemoryRegion *mr)
+{
+ return memory_region_has_guest_memfd(mr) &&
+ (mr->ram_block->flags & RAM_DEFAULT_PRIVATE);
+}
+
+void memory_region_set_default_private(MemoryRegion *mr)
+{
+ if (memory_region_has_guest_memfd(mr)) {
+ mr->ram_block->flags |= RAM_DEFAULT_PRIVATE;
+ }
+}
+
uint8_t memory_region_get_dirty_log_mask(MemoryRegion *mr)
{
uint8_t mask = mr->dirty_log_mask;
--
2.34.1