The SEV VMs have concept of private and shared memory. The private memory
is encrypted with guest-specific key, while shared memory may be encrypted
with hyperivosr key. The KVM_GET_PAGE_ENC_BITMAP can be used to get a
bitmap indicating whether the guest page is private or shared. A private
page must be transmitted using the SEV migration commands.
Add a cpu_physical_memory_sync_encrypted_bitmap() which can be used to get
the page encryption bitmap for a given memory region.
The page encryption bitmap is not exactly same as dirty bitmap. The page
encryption bitmap is a purely a matter of state about the page is encrypted
or not. To avoid some confusion we clone few functions for clarity.
Signed-off-by: Brijesh Singh <brijesh.si...@amd.com>
---
accel/kvm/kvm-all.c | 37 ++++++++
include/exec/ram_addr.h | 199 ++++++++++++++++++++++++++++++++++++++++
include/exec/ramlist.h | 3 +-
migration/ram.c | 17 ++++
4 files changed, 255 insertions(+), 1 deletion(-)
diff --git a/accel/kvm/kvm-all.c b/accel/kvm/kvm-all.c
index f4d136b022..d942e10896 100644
--- a/accel/kvm/kvm-all.c
+++ b/accel/kvm/kvm-all.c
@@ -560,6 +560,36 @@ static int
kvm_get_dirty_pages_log_range(MemoryRegionSection *section,
#define ALIGN(x, y) (((x)+(y)-1) & ~((y)-1))
+/* sync page_enc bitmap */
+static int kvm_sync_page_enc_bitmap(KVMMemoryListener *kml,
+ MemoryRegionSection *section,
+ KVMSlot *mem)
+{
+ unsigned long size;
+ KVMState *s = kvm_state;
+ struct kvm_page_enc_bitmap e = {};
+ ram_addr_t pages = int128_get64(section->size) / getpagesize();
+ ram_addr_t start = section->offset_within_region +
+ memory_region_get_ram_addr(section->mr);
+
+ size = ALIGN(((mem->memory_size) >> TARGET_PAGE_BITS), 64) / 8;
+ e.enc_bitmap = g_malloc0(size);
+ e.start_gfn = mem->start_addr >> TARGET_PAGE_BITS;
+ e.num_pages = pages;
+ if (kvm_vm_ioctl(s, KVM_GET_PAGE_ENC_BITMAP, &e) == -1) {
+ DPRINTF("KVM_GET_PAGE_ENC_BITMAP ioctl failed %d\n", errno);
+ g_free(e.enc_bitmap);
+ return 1;
+ }
+
+ cpu_physical_memory_set_encrypted_lebitmap(e.enc_bitmap,
+ start, pages);
+
+ g_free(e.enc_bitmap);
+
+ return 0;
+}
+
/**
* kvm_physical_sync_dirty_bitmap - Sync dirty bitmap from kernel space
*
@@ -616,6 +646,13 @@ static int
kvm_physical_sync_dirty_bitmap(KVMMemoryListener *kml,
}
kvm_get_dirty_pages_log_range(section, d.dirty_bitmap);
+
+ if (kvm_memcrypt_enabled() &&
+ kvm_sync_page_enc_bitmap(kml, section, mem)) {
+ g_free(d.dirty_bitmap);
+ return -1;
+ }
+
}
out:
return ret;
diff --git a/include/exec/ram_addr.h b/include/exec/ram_addr.h
index b7b2e60ff6..6dbeac6567 100644
--- a/include/exec/ram_addr.h
+++ b/include/exec/ram_addr.h
@@ -67,6 +67,8 @@ struct RAMBlock {
*/
unsigned long *clear_bmap;
uint8_t clear_bmap_shift;
+ /* bitmap of page encryption state for an encrypted guest */
+ unsigned long *encbmap;
};
/**
@@ -323,6 +325,60 @@ static inline void
cpu_physical_memory_set_dirty_flag(ram_addr_t addr,
rcu_read_unlock();
}
+static inline void cpu_physical_memory_set_encrypted_range(ram_addr_t start,
+ ram_addr_t length,
+ unsigned long val)
+{
+ unsigned long page;
+ unsigned long * const *src;
+
+ page = start >> TARGET_PAGE_BITS;
+
+ rcu_read_lock();
+
+ src = atomic_rcu_read(
+ &ram_list.dirty_memory[DIRTY_MEMORY_ENCRYPTED])->blocks;
+
+ if (length) {
+ unsigned long idx = page / DIRTY_MEMORY_BLOCK_SIZE;
+ unsigned long offset = page % DIRTY_MEMORY_BLOCK_SIZE;
+ int m = (start) & (BITS_PER_LONG - 1);
+ int n = MIN(length, BITS_PER_LONG - m);
+ unsigned long old_val = atomic_read(&src[idx][BIT_WORD(offset)]);
+ unsigned long mask;
+
+ mask = (~0UL >> n);
+ mask = mask << m;
+
+ old_val &= ~mask;
+ val &= mask;
+
+ atomic_xchg(&src[idx][BIT_WORD(offset)], old_val | val);
+ page += n;
+ length -= n;
+ }
+
+ /* remaining bits */
+ if (length) {
+ unsigned long idx = page / DIRTY_MEMORY_BLOCK_SIZE;
+ unsigned long offset = page % DIRTY_MEMORY_BLOCK_SIZE;
+ int m = (start) & (BITS_PER_LONG - 1);
+ int n = MIN(length, BITS_PER_LONG - m);
+ unsigned long old_val = atomic_read(&src[idx][BIT_WORD(offset)]);
+ unsigned long mask;
+
+ mask = (~0UL >> n);
+ mask = mask << m;
+
+ old_val &= ~mask;
+ val &= mask;
+
+ atomic_xchg(&src[idx][BIT_WORD(offset)], old_val | val);
+ }
+
+ rcu_read_unlock();
+}
+
static inline void cpu_physical_memory_set_dirty_range(ram_addr_t start,
ram_addr_t length,
uint8_t mask)
@@ -376,6 +432,62 @@ static inline void
cpu_physical_memory_set_dirty_range(ram_addr_t start,
}
#if !defined(_WIN32)
+static inline void cpu_physical_memory_set_encrypted_lebitmap(
+ unsigned long *bitmap,
+ ram_addr_t start,
+ ram_addr_t pages)
+{
+ unsigned long i;
+ unsigned long hpratio = getpagesize() / TARGET_PAGE_SIZE;
+ unsigned long page = BIT_WORD(start >> TARGET_PAGE_BITS);
+
+ /* start address is aligned at the start of a word? */
+ if ((((page * BITS_PER_LONG) << TARGET_PAGE_BITS) == start) &&
+ (hpratio == 1)) {
+ unsigned long **blocks[DIRTY_MEMORY_NUM];
+ unsigned long idx;
+ unsigned long offset;
+ long k;
+ long nr = BITS_TO_LONGS(pages);
+
+ idx = (start >> TARGET_PAGE_BITS) / DIRTY_MEMORY_BLOCK_SIZE;
+ offset = BIT_WORD((start >> TARGET_PAGE_BITS) %
+ DIRTY_MEMORY_BLOCK_SIZE);
+
+ rcu_read_lock();
+
+ for (i = 0; i < DIRTY_MEMORY_NUM; i++) {
+ blocks[i] = atomic_rcu_read(&ram_list.dirty_memory[i])->blocks;
+ }
+
+ for (k = 0; k < nr; k++) {
+ if (bitmap[k]) {
+ unsigned long temp = leul_to_cpu(bitmap[k]);
+
+ atomic_xchg(&blocks[DIRTY_MEMORY_ENCRYPTED][idx][offset],
temp);
+ }
+
+ if (++offset >= BITS_TO_LONGS(DIRTY_MEMORY_BLOCK_SIZE)) {
+ offset = 0;
+ idx++;
+ }
+ }
+
+ rcu_read_unlock();
+ } else {
+ i = 0;
+ while (pages > 0) {
+ unsigned long len = MIN(pages, BITS_PER_LONG);
+
+ cpu_physical_memory_set_encrypted_range(start, len,
+ leul_to_cpu(bitmap[i]));
+ start += len;
+ i++;
+ pages -= len;
+ }
+ }
+}
+
static inline void cpu_physical_memory_set_dirty_lebitmap(unsigned long
*bitmap,
ram_addr_t start,
ram_addr_t pages)
@@ -478,6 +590,8 @@ static inline void
cpu_physical_memory_clear_dirty_range(ram_addr_t start,
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);
+ cpu_physical_memory_test_and_clear_dirty(start, length,
+ DIRTY_MEMORY_ENCRYPTED);
}
@@ -556,5 +670,90 @@ uint64_t cpu_physical_memory_sync_dirty_bitmap(RAMBlock
*rb,
return num_dirty;
}
+
+static inline bool cpu_physical_memory_test_encrypted(ram_addr_t start,
+ ram_addr_t length)
+{
+ unsigned long end, page;
+ bool enc = false;
+ unsigned long * const *src;
+
+ if (length == 0) {
+ return enc;
+ }
+
+ end = TARGET_PAGE_ALIGN(start + length) >> TARGET_PAGE_BITS;
+ page = start >> TARGET_PAGE_BITS;
+
+ rcu_read_lock();
+
+ src = atomic_rcu_read(
+ &ram_list.dirty_memory[DIRTY_MEMORY_ENCRYPTED])->blocks;
+
+ while (page < end) {
+ unsigned long idx = page / DIRTY_MEMORY_BLOCK_SIZE;
+ unsigned long offset = page % DIRTY_MEMORY_BLOCK_SIZE;
+ unsigned long num = MIN(end - page, DIRTY_MEMORY_BLOCK_SIZE - offset);
+
+ enc |= atomic_read(&src[idx][BIT_WORD(offset)]);
+ page += num;
+ }
+
+ rcu_read_unlock();
+
+ return enc;
+}
+
+static inline
+void cpu_physical_memory_sync_encrypted_bitmap(RAMBlock *rb,
+ ram_addr_t start,
+ ram_addr_t length)
+{
+ ram_addr_t addr;
+ unsigned long word = BIT_WORD((start + rb->offset) >> TARGET_PAGE_BITS);
+ unsigned long *dest = rb->encbmap;
+
+ /* start address and length is aligned at the start of a word? */
+ if (((word * BITS_PER_LONG) << TARGET_PAGE_BITS) ==
+ (start + rb->offset) &&
+ !(length & ((BITS_PER_LONG << TARGET_PAGE_BITS) - 1))) {
+ int k;
+ int nr = BITS_TO_LONGS(length >> TARGET_PAGE_BITS);
+ unsigned long * const *src;
+ unsigned long idx = (word * BITS_PER_LONG) / DIRTY_MEMORY_BLOCK_SIZE;
+ unsigned long offset = BIT_WORD((word * BITS_PER_LONG) %
+ DIRTY_MEMORY_BLOCK_SIZE);
+ unsigned long page = BIT_WORD(start >> TARGET_PAGE_BITS);
+
+ rcu_read_lock();
+
+ src = atomic_rcu_read(
+ &ram_list.dirty_memory[DIRTY_MEMORY_ENCRYPTED])->blocks;
+
+ for (k = page; k < page + nr; k++) {
+ unsigned long bits = atomic_read(&src[idx][offset]);
+ dest[k] = bits;
+
+ if (++offset >= BITS_TO_LONGS(DIRTY_MEMORY_BLOCK_SIZE)) {
+ offset = 0;
+ idx++;
+ }
+ }
+
+ rcu_read_unlock();
+ } else {
+ ram_addr_t offset = rb->offset;
+
+ for (addr = 0; addr < length; addr += TARGET_PAGE_SIZE) {
+ long k = (start + addr) >> TARGET_PAGE_BITS;
+ if (cpu_physical_memory_test_encrypted(start + addr + offset,
+ TARGET_PAGE_SIZE)) {
+ set_bit(k, dest);
+ } else {
+ clear_bit(k, dest);
+ }
+ }
+ }
+}
#endif
#endif
diff --git a/include/exec/ramlist.h b/include/exec/ramlist.h
index bc4faa1b00..2a5eab8b11 100644
--- a/include/exec/ramlist.h
+++ b/include/exec/ramlist.h
@@ -11,7 +11,8 @@ typedef struct RAMBlockNotifier RAMBlockNotifier;
#define DIRTY_MEMORY_VGA 0
#define DIRTY_MEMORY_CODE 1
#define DIRTY_MEMORY_MIGRATION 2
-#define DIRTY_MEMORY_NUM 3 /* num of dirty bits */
+#define DIRTY_MEMORY_ENCRYPTED 3
+#define DIRTY_MEMORY_NUM 4 /* num of dirty bits */
/* The dirty memory bitmap is split into fixed-size blocks to allow growth
* under RCU. The bitmap for a block can be accessed as follows:
diff --git a/migration/ram.c b/migration/ram.c
index 889148dd84..57c707525b 100644
--- a/migration/ram.c
+++ b/migration/ram.c
@@ -57,6 +57,7 @@
#include "qemu/uuid.h"
#include "savevm.h"
#include "qemu/iov.h"
+#include "hw/boards.h"
/***********************************************************/
/* ram save/restore */
@@ -700,6 +701,13 @@ typedef struct {
QemuSemaphore sem_sync;
} MultiFDRecvParams;
+static inline bool memcrypt_enabled(void)
+{
+ MachineState *ms = MACHINE(qdev_get_machine());
+
+ return machine_memory_encryption_enabled(ms);
+}
+
static int multifd_send_initial_packet(MultiFDSendParams *p, Error **errp)
{
MultiFDInit_t msg;
@@ -1754,6 +1762,9 @@ static void migration_bitmap_sync_range(RAMState *rs,
RAMBlock *rb,
rs->migration_dirty_pages +=
cpu_physical_memory_sync_dirty_bitmap(rb, 0, length,
&rs->num_dirty_pages_period);
+ if (memcrypt_enabled()) {
+ cpu_physical_memory_sync_encrypted_bitmap(rb, 0, length);
+ }
}
/**
@@ -2768,6 +2779,8 @@ static void ram_save_cleanup(void *opaque)
block->bmap = NULL;
g_free(block->unsentmap);
block->unsentmap = NULL;
+ g_free(block->encbmap);
+ block->encbmap = NULL;
}
xbzrle_cleanup();
@@ -3310,6 +3323,10 @@ static void ram_list_init_bitmaps(void)
block->unsentmap = bitmap_new(pages);
bitmap_set(block->unsentmap, 0, pages);
}
+ if (memcrypt_enabled()) {
+ block->encbmap = bitmap_new(pages);
+ bitmap_set(block->encbmap, 0, pages);
+ }
}
}
}
--
2.17.1
