On 3/20/24 09:39, Michael Roth wrote:
From: Xiaoyao Li <xiaoyao.li@xxxxxxxxx>
Introduce the helper functions to set the attributes of a range of
memory to private or shared.
This is necessary to notify KVM the private/shared attribute of each gpa
range. KVM needs the information to decide the GPA needs to be mapped at
hva-based shared memory or guest_memfd based private memory.
Signed-off-by: Xiaoyao Li <xiaoyao.li@xxxxxxxxx>
---
Changes in v4:
- move the check of kvm_supported_memory_attributes to the common
kvm_set_memory_attributes(); (Wang Wei)
- change warn_report() to error_report() in kvm_set_memory_attributes()
and drop the __func__; (Daniel)
Signed-off-by: Michael Roth <michael.roth@xxxxxxx>
---
accel/kvm/kvm-all.c | 44 ++++++++++++++++++++++++++++++++++++++++++++
include/sysemu/kvm.h | 3 +++
2 files changed, 47 insertions(+)
diff --git a/accel/kvm/kvm-all.c b/accel/kvm/kvm-all.c
index e83429b31e..df7a32735a 100644
--- a/accel/kvm/kvm-all.c
+++ b/accel/kvm/kvm-all.c
@@ -92,6 +92,7 @@ static bool kvm_has_guest_debug;
static int kvm_sstep_flags;
static bool kvm_immediate_exit;
static bool kvm_guest_memfd_supported;
+static uint64_t kvm_supported_memory_attributes;
static hwaddr kvm_max_slot_size = ~0;
static const KVMCapabilityInfo kvm_required_capabilites[] = {
@@ -1304,6 +1305,46 @@ void kvm_set_max_memslot_size(hwaddr max_slot_size)
kvm_max_slot_size = max_slot_size;
}
+static int kvm_set_memory_attributes(hwaddr start, hwaddr size, uint64_t attr)
+{
+ struct kvm_memory_attributes attrs;
+ int r;
+
+ if (kvm_supported_memory_attributes == 0) {
+ error_report("No memory attribute supported by KVM\n");
+ return -EINVAL;
+ }
+
+ if ((attr & kvm_supported_memory_attributes) != attr) {
+ error_report("memory attribute 0x%lx not supported by KVM,"
+ " supported bits are 0x%lx\n",
+ attr, kvm_supported_memory_attributes);
+ return -EINVAL;
+ }
This should also be tested at the same time as kvm_guest_memfd_supported.
Paolo
+ attrs.attributes = attr;
+ attrs.address = start;
+ attrs.size = size;
+ attrs.flags = 0;
+
+ r = kvm_vm_ioctl(kvm_state, KVM_SET_MEMORY_ATTRIBUTES, &attrs);
+ if (r) {
+ error_report("failed to set memory (0x%lx+%#zx) with attr 0x%lx error '%s'",
+ start, size, attr, strerror(errno));
+ }
+ return r;
+}
+
+int kvm_set_memory_attributes_private(hwaddr start, hwaddr size)
+{
+ return kvm_set_memory_attributes(start, size, KVM_MEMORY_ATTRIBUTE_PRIVATE);
+}
+
+int kvm_set_memory_attributes_shared(hwaddr start, hwaddr size)
+{
+ return kvm_set_memory_attributes(start, size, 0);
+}
+
/* Called with KVMMemoryListener.slots_lock held */
static void kvm_set_phys_mem(KVMMemoryListener *kml,
MemoryRegionSection *section, bool add)
@@ -2439,6 +2480,9 @@ static int kvm_init(MachineState *ms)
kvm_guest_memfd_supported = kvm_check_extension(s, KVM_CAP_GUEST_MEMFD);
+ ret = kvm_check_extension(s, KVM_CAP_MEMORY_ATTRIBUTES);
+ kvm_supported_memory_attributes = ret > 0 ? ret : 0;
+
if (object_property_find(OBJECT(current_machine), "kvm-type")) {
g_autofree char *kvm_type = object_property_get_str(OBJECT(current_machine),
"kvm-type",
diff --git a/include/sysemu/kvm.h b/include/sysemu/kvm.h
index b4913281e2..2cb3192509 100644
--- a/include/sysemu/kvm.h
+++ b/include/sysemu/kvm.h
@@ -538,4 +538,7 @@ void kvm_mark_guest_state_protected(void);
bool kvm_hwpoisoned_mem(void);
int kvm_create_guest_memfd(uint64_t size, uint64_t flags, Error **errp);
+
+int kvm_set_memory_attributes_private(hwaddr start, hwaddr size);
+int kvm_set_memory_attributes_shared(hwaddr start, hwaddr size);
#endif
This suggests that
