KVM: SEV: Do cache maintenance on the source VM during intra-host migrationgrafted

Manually perform cache maintenance on the source VM during intra-host
migration to ensure no stale data is left in CPU caches after the VM is
destroyed.  Because the source VM is "converted" to a non-SEV VM, KVM's
memory reclaim flows won't trigger cache maintenance, e.g. when all guest
memory is reclaimed in response to detaching from the mmu_notifier.

Note, relying on the destination VM to do cache maintenance isn't an option
as KVM doesn't require identical guest memory configurations, i.e. the
source VM may have access to memory that the destination VM does not.
Enforcing equivalent memory configurations is infeasible, as it would
require a *deep* comparison of memslots, e.g. to verify that not only are
the memslot identical, but what the memslots point at is also identical.

Fixes: b56639318bb2 ("KVM: SEV: Add support for SEV intra host migration")
Cc: stable@vger.kernel.org
Reported-by: Stefan Teodorescu <fane@google.com>
Signed-off-by: Sean Christopherson <seanjc@google.com>
Message-ID: <20260923163721.1584779-3-seanjc@google.com>
Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>

1 files changed, 263 insertions, 0 deletions

diff --git a/drivers/scsi/nsp32_debug.c b/drivers/scsi/nsp32_debug.c
new file mode 100644
index 000000000..4f1d4bf9c
--- /dev/null
+++ b/drivers/scsi/nsp32_debug.c
@@ -0,0 +1,263 @@
+/*
+ * Workbit NinjaSCSI-32Bi/UDE PCI/CardBus SCSI Host Bus Adapter driver
+ * Debug routine
+ *
+ * This software may be used and distributed according to the terms of
+ * the GNU General Public License.
+ */
+
+/*
+ * Show the command data of a command
+ */
+static const char unknown[] = "UNKNOWN";
+
+static const char * group_0_commands[] = {
+/* 00-03 */ "Test Unit Ready", "Rezero Unit", unknown, "Request Sense",
+/* 04-07 */ "Format Unit", "Read Block Limits", unknown, "Reassign Blocks",
+/* 08-0d */ "Read (6)", unknown, "Write (6)", "Seek (6)", unknown, unknown,
+/* 0e-12 */ unknown, "Read Reverse", "Write Filemarks", "Space", "Inquiry",  
+/* 13-16 */ unknown, "Recover Buffered Data", "Mode Select", "Reserve",
+/* 17-1b */ "Release", "Copy", "Erase", "Mode Sense", "Start/Stop Unit",
+/* 1c-1d */ "Receive Diagnostic", "Send Diagnostic", 
+/* 1e-1f */ "Prevent/Allow Medium Removal", unknown,
+};
+
+
+static const char *group_1_commands[] = {
+/* 20-22 */  unknown, unknown, unknown,
+/* 23-28 */ unknown, unknown, "Read Capacity", unknown, unknown, "Read (10)",
+/* 29-2d */ unknown, "Write (10)", "Seek (10)", unknown, unknown,
+/* 2e-31 */ "Write Verify","Verify", "Search High", "Search Equal",
+/* 32-34 */ "Search Low", "Set Limits", "Prefetch or Read Position", 
+/* 35-37 */ "Synchronize Cache","Lock/Unlock Cache", "Read Defect Data",
+/* 38-3c */ "Medium Scan", "Compare","Copy Verify", "Write Buffer", "Read Buffer",
+/* 3d-3f */ "Update Block", "Read Long",  "Write Long",
+};
+
+
+static const char *group_2_commands[] = {
+/* 40-41 */ "Change Definition", "Write Same", 
+/* 42-48 */ "Read Sub-Ch(cd)", "Read TOC", "Read Header(cd)", "Play Audio(cd)", unknown, "Play Audio MSF(cd)", "Play Audio Track/Index(cd)", 
+/* 49-4f */ "Play Track Relative(10)(cd)", unknown, "Pause/Resume(cd)", "Log Select", "Log Sense", unknown, unknown,
+/* 50-55 */ unknown, unknown, unknown, unknown, unknown, "Mode Select (10)",
+/* 56-5b */ unknown, unknown, unknown, unknown, "Mode Sense (10)", unknown,
+/* 5c-5f */ unknown, unknown, unknown,
+};
+
+#define group(opcode) (((opcode) >> 5) & 7)
+
+#define RESERVED_GROUP  0
+#define VENDOR_GROUP    1
+#define NOTEXT_GROUP    2
+
+static const char **commands[] = {
+    group_0_commands, group_1_commands, group_2_commands, 
+    (const char **) RESERVED_GROUP, (const char **) RESERVED_GROUP, 
+    (const char **) NOTEXT_GROUP, (const char **) VENDOR_GROUP, 
+    (const char **) VENDOR_GROUP
+};
+
+static const char reserved[] = "RESERVED";
+static const char vendor[] = "VENDOR SPECIFIC";
+
+static void print_opcodek(unsigned char opcode)
+{
+	const char **table = commands[ group(opcode) ];
+
+	switch ((unsigned long) table) {
+	case RESERVED_GROUP:
+		printk("%s[%02x] ", reserved, opcode); 
+		break;
+	case NOTEXT_GROUP:
+		printk("%s(notext)[%02x] ", unknown, opcode); 
+		break;
+	case VENDOR_GROUP:
+		printk("%s[%02x] ", vendor, opcode); 
+		break;
+	default:
+		if (table[opcode & 0x1f] != unknown)
+			printk("%s[%02x] ", table[opcode & 0x1f], opcode);
+		else
+			printk("%s[%02x] ", unknown, opcode);
+		break;
+	}
+}
+
+static void print_commandk (unsigned char *command)
+{
+	int i,s;
+//	printk(KERN_DEBUG);
+	print_opcodek(command[0]);
+	/*printk(KERN_DEBUG "%s ", __func__);*/
+	if ((command[0] >> 5) == 6 ||
+	    (command[0] >> 5) == 7 ) {
+		s = 12; /* vender specific */
+	} else {
+		s = COMMAND_SIZE(command[0]);
+	}
+
+	for ( i = 1; i < s; ++i) {
+		printk("%02x ", command[i]);
+	}
+
+	switch (s) {
+	case 6:
+		printk("LBA=%d len=%d",
+		       (((unsigned int)command[1] & 0x0f) << 16) |
+		       ( (unsigned int)command[2]         <<  8) |
+		       ( (unsigned int)command[3]              ),
+		       (unsigned int)command[4]
+			);
+		break;
+	case 10:
+		printk("LBA=%d len=%d",
+		       ((unsigned int)command[2] << 24) |
+		       ((unsigned int)command[3] << 16) |
+		       ((unsigned int)command[4] <<  8) |
+		       ((unsigned int)command[5]      ),
+		       ((unsigned int)command[7] <<  8) |
+		       ((unsigned int)command[8]      )
+		       );
+		break;
+	case 12:
+		printk("LBA=%d len=%d",
+		       ((unsigned int)command[2] << 24) |
+		       ((unsigned int)command[3] << 16) |
+		       ((unsigned int)command[4] <<  8) |
+		       ((unsigned int)command[5]      ),
+		       ((unsigned int)command[6] << 24) |
+		       ((unsigned int)command[7] << 16) |
+		       ((unsigned int)command[8] <<  8) |
+		       ((unsigned int)command[9]      )
+		       );
+		break;
+	default:
+		break;
+	}
+	printk("\n");
+}
+
+static void show_command(struct scsi_cmnd *SCpnt)
+{
+	print_commandk(SCpnt->cmnd);
+}
+
+static void show_busphase(unsigned char stat)
+{
+	switch(stat) {
+	case BUSPHASE_COMMAND:
+		printk( "BUSPHASE_COMMAND\n");
+		break;
+	case BUSPHASE_MESSAGE_IN:
+		printk( "BUSPHASE_MESSAGE_IN\n");
+		break;
+	case BUSPHASE_MESSAGE_OUT:
+		printk( "BUSPHASE_MESSAGE_OUT\n");
+		break;
+	case BUSPHASE_DATA_IN:
+		printk( "BUSPHASE_DATA_IN\n");
+		break;
+	case BUSPHASE_DATA_OUT:
+		printk( "BUSPHASE_DATA_OUT\n");
+		break;
+	case BUSPHASE_STATUS:
+		printk( "BUSPHASE_STATUS\n");
+		break;
+	case BUSPHASE_SELECT:
+		printk( "BUSPHASE_SELECT\n");
+		break;
+	default:
+		printk( "BUSPHASE_other: 0x%x\n", stat);
+		break;
+	}
+}
+
+static void show_autophase(unsigned short i)
+{
+	printk("auto: 0x%x,", i);
+
+	if(i & COMMAND_PHASE) {
+		printk(" cmd");
+	}
+	if(i & DATA_IN_PHASE) {
+		printk(" din");
+	}
+	if(i & DATA_OUT_PHASE) {
+		printk(" dout");
+	}
+	if(i & MSGOUT_PHASE) {
+		printk(" mout");
+	}
+	if(i & STATUS_PHASE) {
+		printk(" stat");
+	}
+	if(i & ILLEGAL_PHASE) {
+		printk(" ill");
+	}
+	if(i & BUS_FREE_OCCUER) {
+		printk(" bfree-o");
+	}
+	if(i & MSG_IN_OCCUER) {
+		printk(" min-o");
+	}
+	if(i & MSG_OUT_OCCUER) {
+		printk(" mout-o");
+	}
+	if(i & SELECTION_TIMEOUT) {
+		printk(" sel");
+	}
+	if(i & MSGIN_00_VALID) {
+		printk(" m0");
+	}
+	if(i & MSGIN_02_VALID) {
+		printk(" m2");
+	}
+	if(i & MSGIN_03_VALID) {
+		printk(" m3");
+	}
+	if(i & MSGIN_04_VALID) {
+		printk(" m4");
+	}
+	if(i & AUTOSCSI_BUSY) {
+		printk(" busy");
+	}
+
+	printk("\n");
+}
+
+static void nsp32_print_register(int base)
+{
+	if (!(NSP32_DEBUG_MASK & NSP32_SPECIAL_PRINT_REGISTER))
+		return;
+
+	printk("Phase=0x%x, ", nsp32_read1(base, SCSI_BUS_MONITOR));
+	printk("OldPhase=0x%x, ", nsp32_index_read1(base, OLD_SCSI_PHASE));
+	printk("syncreg=0x%x, ", nsp32_read1(base, SYNC_REG));
+	printk("ackwidth=0x%x, ", nsp32_read1(base, ACK_WIDTH));
+	printk("sgtpaddr=0x%lx, ", nsp32_read4(base, SGT_ADR));
+	printk("scsioutlatch=0x%x, ", nsp32_read1(base, SCSI_OUT_LATCH_TARGET_ID));
+	printk("msgout=0x%lx, ", nsp32_read4(base, SCSI_MSG_OUT));
+	printk("miscrd=0x%x, ", nsp32_index_read2(base, MISC_WR));
+	printk("seltimeout=0x%x, ", nsp32_read2(base, SEL_TIME_OUT));
+	printk("sreqrate=0x%x, ", nsp32_read1(base, SREQ_SMPL_RATE));
+	printk("transStatus=0x%x, ", nsp32_read2(base, TRANSFER_STATUS));
+	printk("reselectid=0x%x, ", nsp32_read2(base, COMMAND_CONTROL));
+	printk("arbit=0x%x, ", nsp32_read1(base, ARBIT_STATUS));
+	printk("BmStart=0x%lx, ", nsp32_read4(base, BM_START_ADR));
+	printk("BmCount=0x%lx, ", nsp32_read4(base, BM_CNT));
+	printk("SackCnt=0x%lx, ", nsp32_read4(base, SACK_CNT));
+	printk("SReqCnt=0x%lx, ", nsp32_read4(base, SREQ_CNT));
+	printk("SavedSackCnt=0x%lx, ", nsp32_read4(base, SAVED_SACK_CNT));
+	printk("ScsiBusControl=0x%x, ", nsp32_read1(base, SCSI_BUS_CONTROL));
+	printk("FifoRestCnt=0x%x, ", nsp32_read2(base, FIFO_REST_CNT));
+	printk("CdbIn=0x%x, ", nsp32_read1(base, SCSI_CSB_IN));
+	printk("\n");
+
+	if (0) {
+		printk("execph=0x%x, ", nsp32_read2(base, SCSI_EXECUTE_PHASE));
+		printk("IrqStatus=0x%x, ", nsp32_read2(base, IRQ_STATUS));
+		printk("\n");
+	}
+}
+
+/* end */