On 9/4/26 5:35 AM, Mathieu Poirier wrote:
From: Jean-Philippe Brucker <[email protected]>
Once the Realm descriptor has been created, tell KVM to transfer runtime
images (kernel, DT, and rootfs) from guest memory to Realm memory.
Signed-off-by: Jean-Philippe Brucker <[email protected]>
Signed-off-by: Lorenzo Pieralisi <[email protected]>
Signed-off-by: Mathieu Poirier <[email protected]>
---
target/arm/kvm-rme.c | 76 ++++++++++++++++++++++++++++++++++++++++++++
1 file changed, 76 insertions(+)
diff --git a/target/arm/kvm-rme.c b/target/arm/kvm-rme.c
index 9985f5daba89..c082a5d8f3d1 100644
--- a/target/arm/kvm-rme.c
+++ b/target/arm/kvm-rme.c
@@ -15,6 +15,7 @@
#include "migration/blocker.h"
#include "qapi/error.h"
#include "qemu/error-report.h"
+#include "qemu/memalign.h"
#include "qom/object_interfaces.h"
#include "system/confidential-guest-support.h"
#include "system/kvm.h"
@@ -43,12 +44,87 @@ OBJECT_DEFINE_SIMPLE_TYPE_WITH_INTERFACES(RmeGuest,
rme_guest, RME_GUEST,
static RmeGuest *rme_guest;
+static int rme_populate_range(const RmeRamRegion *region, bool measure,
+ Error **errp)
+{
+ int ret;
+ void *buffer;
+ hwaddr size = region->size;
+ hwaddr base = region->base;
+ hwaddr start = QEMU_ALIGN_DOWN(base, RME_PAGE_SIZE);
+ hwaddr end = QEMU_ALIGN_UP(base + size, RME_PAGE_SIZE);
+ struct kvm_arm_rmi_populate populate_args;
+ size_t aligned_size = ROUND_UP(region->size, qemu_real_host_page_size());
s/qemu_real_host_page_size()/RME_PAGE_SIZE
+
+ if (!region->data) {
+ return -ENODEV;
+ }
+
+ ret = kvm_set_memory_attributes_private(start, end - start);
+ if (ret) {
+ error_report("RME: failed to configure initial"
+ "private guest memory");
+ return ret;
+ }
+
+ /* Allocate page-aligned memory */
+ buffer = qemu_memalign(qemu_real_host_page_size(), aligned_size);
+
+ if (!buffer) {
+ return -ENOMEM;
+ }
+
+ memset(buffer, 0, aligned_size);
+ memcpy(buffer, region->data, region->size);
+
+ populate_args = (struct kvm_arm_rmi_populate) {
+ .base = start,
+ .size = end - start,
+ .source_uaddr = (uintptr_t)buffer,
+ .flags = measure ? KVM_ARM_RMI_POPULATE_FLAGS_MEASURE : 0,
+ };
+
+ while (populate_args.size > 0) {
+ ret = kvm_vm_ioctl(kvm_state, KVM_ARM_RMI_POPULATE, &populate_args, 0);
+ if (ret) {
+ error_setg_errno(errp, -ret,
+ "failed to populate realm [0x%"HWADDR_PRIx",
0x%"HWADDR_PRIx")",
+ start, end);
+ break;
+ }
+ }
+
+ qemu_vfree(buffer);
+
+ return ret;
+}
+
I doubt that the unaligned regions (RmeRamRegion) are allowed. For example,
the region [4KB 64KB+4KB] is turned to the aligned range [0 128KB] when
RME_PAGE_SIZE
is 64KB. The question is how do we know the added regions due to the alignment
([0 4KB] and [64KB+4KB 128KB]) are safe for kvm_vm_ioctl(KVM_ARM_RMI_POPULATE).
I guess we probably just reject unaligned regions if they're not expected.
Even if the unaligned regions are allowed, they seem not well handled.
- @aligned_size is still 64KB instead of the 128KB ?
- In "memcpy(buffer, region->data, region->size);", the blob data would be
copied to
[4KB, 4KB+64KB]. However, we're copying the data to [0 64KB] now.
+static void rme_populate_ram_region(gpointer data, gpointer err)
+{
+ Error **errp = err;
+ const RmeRamRegion *region = data;
+
+ if (*errp) {
+ return;
+ }
+
+ rme_populate_range(region, /* measure */ true, errp);
+}
+
static void rme_vm_state_change(void *opaque, bool running, RunState state)
{
+ Error *errp = NULL;
+
if (!running) {
return;
}
+ g_slist_foreach(rme_guest->ram_regions, rme_populate_ram_region, &errp);
+ g_slist_free_full(g_steal_pointer(&rme_guest->ram_regions), g_free);
+ if (errp) {
+ return;
+ }
+
kvm_mark_guest_state_protected();
}
Thanks,
Gavin
