From: Brijesh Singh <brijesh.singh@xxxxxxx>
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.
[Dov changes: replace memcrypt-related checkers with confidential guest
support in migration/ram.c and accel/kvm; rename atomic_* to qatomic_*
in include/exec/ram_addr.h]
Signed-off-by: Brijesh Singh <brijesh.singh@xxxxxxx>
Signed-off-by: Dov Murik <dovmurik@xxxxxxxxxxxxxxxxxx>
---
include/exec/ram_addr.h | 197 ++++++++++++++++++++++++++++++++++++++++
include/exec/ramblock.h | 3 +
include/exec/ramlist.h | 3 +-
accel/kvm/kvm-all.c | 43 +++++++++
migration/ram.c | 17 ++++
5 files changed, 262 insertions(+), 1 deletion(-)
diff --git a/include/exec/ram_addr.h b/include/exec/ram_addr.h
index 3cb9791df3..aac5b5e393 100644
--- a/include/exec/ram_addr.h
+++ b/include/exec/ram_addr.h
@@ -284,6 +284,60 @@ static inline void cpu_physical_memory_set_dirty_flag(ram_addr_t addr,
set_bit_atomic(offset, blocks->blocks[idx]);
}
+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 = qatomic_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 = qatomic_read(&src[idx][BIT_WORD(offset)]);
+ unsigned long mask;
+
+ mask = (~0UL >> n);
+ mask = mask << m;
+
+ old_val &= ~mask;
+ val &= mask;
+
+ qatomic_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 = qatomic_read(&src[idx][BIT_WORD(offset)]);
+ unsigned long mask;
+
+ mask = (~0UL >> n);
+ mask = mask << m;
+
+ old_val &= ~mask;
+ val &= mask;
+
+ qatomic_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)
@@ -335,6 +389,62 @@ 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] = qatomic_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]);
+
+ qatomic_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)
@@ -438,6 +548,8 @@ 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);
}
@@ -513,5 +625,90 @@ 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 = qatomic_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 |= qatomic_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 = qatomic_rcu_read(
+ &ram_list.dirty_memory[DIRTY_MEMORY_ENCRYPTED])->blocks;
+
+ for (k = page; k < page + nr; k++) {
+ unsigned long bits = qatomic_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/ramblock.h b/include/exec/ramblock.h
index 07d50864d8..bcd7720826 100644
--- a/include/exec/ramblock.h
+++ b/include/exec/ramblock.h
@@ -59,6 +59,9 @@ struct RAMBlock {
*/
unsigned long *clear_bmap;
uint8_t clear_bmap_shift;
+
+ /* bitmap of page encryption state for an encrypted guest */
+ unsigned long *encbmap;
};
#endif
#endif
diff --git a/include/exec/ramlist.h b/include/exec/ramlist.h
index 26704aa3b0..2422e5ce86 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/accel/kvm/kvm-all.c b/accel/kvm/kvm-all.c
index 84c943fcdb..13350c1b9b 100644
--- a/accel/kvm/kvm-all.c
+++ b/accel/kvm/kvm-all.c
@@ -604,6 +604,43 @@ static void kvm_memslot_init_dirty_bitmap(KVMSlot *mem)
mem->dirty_bmap = g_malloc0(bitmap_size);
}
+/* 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;
+}
+
+static inline bool confidential_guest(void)
+{
+ MachineState *ms = MACHINE(qdev_get_machine());
+
+ return ms->cgs;
+}
+
/**
* kvm_physical_sync_dirty_bitmap - Sync dirty bitmap from kernel space
*
@@ -659,6 +696,12 @@ static int kvm_physical_sync_dirty_bitmap(KVMMemoryListener *kml,
slot_offset += slot_size;
start_addr += slot_size;
size -= slot_size;
+
+ if (confidential_guest() &&
+ kvm_sync_page_enc_bitmap(kml, section, mem)) {
+ g_free(d.dirty_bitmap);
+ return -1;
+ }
}
out:
return ret;
diff --git a/migration/ram.c b/migration/ram.c
index 72143da0ac..997f90cc5b 100644
--- a/migration/ram.c
+++ b/migration/ram.c
@@ -61,6 +61,7 @@
#if defined(__linux__)
#include "qemu/userfaultfd.h"
#endif /* defined(__linux__) */
+#include "hw/boards.h"
/***********************************************************/
/* ram save/restore */
@@ -81,6 +82,13 @@
/* 0x80 is reserved in migration.h start with 0x100 next */
#define RAM_SAVE_FLAG_COMPRESS_PAGE 0x100
+static inline bool memcrypt_enabled(void)
+{
+ MachineState *ms = MACHINE(qdev_get_machine());
+
+ return ms->cgs;
+}
+
static inline bool is_zero_range(uint8_t *p, uint64_t size)
{
return buffer_is_zero(p, size);
@@ -865,6 +873,9 @@ static void ramblock_sync_dirty_bitmap(RAMState *rs, RAMBlock *rb)
rs->migration_dirty_pages += new_dirty_pages;
rs->num_dirty_pages_period += new_dirty_pages;
+ if (memcrypt_enabled()) {
+ cpu_physical_memory_sync_encrypted_bitmap(rb, 0, rb->used_length);
+ }
}
/**
@@ -2174,6 +2185,8 @@ static void ram_save_cleanup(void *opaque)
block->clear_bmap = NULL;
g_free(block->bmap);
block->bmap = NULL;
+ g_free(block->encbmap);
+ block->encbmap = NULL;
}
xbzrle_cleanup();
@@ -2615,6 +2628,10 @@ static void ram_list_init_bitmaps(void)
bitmap_set(block->bmap, 0, pages);
block->clear_bmap_shift = shift;
block->clear_bmap = bitmap_new(clear_bmap_size(pages, shift));
+ if (memcrypt_enabled()) {
+ block->encbmap = bitmap_new(pages);
+ bitmap_set(block->encbmap, 0, pages);
+ }
}
}
}
--
2.20.1
