If SEV is enabled and a kernel is passed via -kernel, pass the hashes of
kernel/initrd/cmdline in an encrypted guest page to OVMF for SEV
measured boot.
Co-developed-by: James Bottomley <j...@linux.ibm.com>
Signed-off-by: James Bottomley <j...@linux.ibm.com>
Signed-off-by: Dov Murik <dovmu...@linux.ibm.com>
Reviewed-by: Connor Kuehl <cku...@redhat.com>
---
hw/i386/x86.c | 25 ++++++++++++++++++++++++-
1 file changed, 24 insertions(+), 1 deletion(-)
diff --git a/hw/i386/x86.c b/hw/i386/x86.c
index d30cf27e29..830c8f6f58 100644
--- a/hw/i386/x86.c
+++ b/hw/i386/x86.c
@@ -45,6 +45,7 @@
#include "hw/i386/fw_cfg.h"
#include "hw/intc/i8259.h"
#include "hw/rtc/mc146818rtc.h"
+#include "target/i386/sev_i386.h"
#include "hw/acpi/cpu_hotplug.h"
#include "hw/irq.h"
@@ -778,6 +779,7 @@ void x86_load_linux(X86MachineState *x86ms,
const char *initrd_filename = machine->initrd_filename;
const char *dtb_filename = machine->dtb;
const char *kernel_cmdline = machine->kernel_cmdline;
+ KernelLoaderContext kernel_loader_context = {};
/* Align to 16 bytes as a paranoia measure */
cmdline_size = (strlen(kernel_cmdline) + 16) & ~15;
@@ -924,6 +926,8 @@ void x86_load_linux(X86MachineState *x86ms,
fw_cfg_add_i32(fw_cfg, FW_CFG_CMDLINE_ADDR, cmdline_addr);
fw_cfg_add_i32(fw_cfg, FW_CFG_CMDLINE_SIZE, strlen(kernel_cmdline) + 1);
fw_cfg_add_string(fw_cfg, FW_CFG_CMDLINE_DATA, kernel_cmdline);
+ kernel_loader_context.cmdline_data = (char *)kernel_cmdline;
+ kernel_loader_context.cmdline_size = strlen(kernel_cmdline) + 1;
if (protocol >= 0x202) {
stl_p(header + 0x228, cmdline_addr);
@@ -1005,6 +1009,8 @@ void x86_load_linux(X86MachineState *x86ms,
fw_cfg_add_i32(fw_cfg, FW_CFG_INITRD_ADDR, initrd_addr);
fw_cfg_add_i32(fw_cfg, FW_CFG_INITRD_SIZE, initrd_size);
fw_cfg_add_bytes(fw_cfg, FW_CFG_INITRD_DATA, initrd_data, initrd_size);
+ kernel_loader_context.initrd_data = initrd_data;
+ kernel_loader_context.initrd_size = initrd_size;
stl_p(header + 0x218, initrd_addr);
stl_p(header + 0x21c, initrd_size);
@@ -1063,15 +1069,32 @@ void x86_load_linux(X86MachineState *x86ms,
load_image_size(dtb_filename, setup_data->data, dtb_size);
}
- memcpy(setup, header, MIN(sizeof(header), setup_size));
+ /*
+ * If we're starting an encrypted VM, it will be OVMF based, which uses the
+ * efi stub for booting and doesn't require any values to be placed in the
+ * kernel header. We therefore don't update the header so the hash of the
+ * kernel on the other side of the fw_cfg interface matches the hash of the
+ * file the user passed in.
+ */
+ if (!sev_enabled()) {
+ memcpy(setup, header, MIN(sizeof(header), setup_size));
+ }
fw_cfg_add_i32(fw_cfg, FW_CFG_KERNEL_ADDR, prot_addr);
fw_cfg_add_i32(fw_cfg, FW_CFG_KERNEL_SIZE, kernel_size);
fw_cfg_add_bytes(fw_cfg, FW_CFG_KERNEL_DATA, kernel, kernel_size);
+ kernel_loader_context.kernel_data = (char *)kernel;
+ kernel_loader_context.kernel_size = kernel_size;
fw_cfg_add_i32(fw_cfg, FW_CFG_SETUP_ADDR, real_addr);
fw_cfg_add_i32(fw_cfg, FW_CFG_SETUP_SIZE, setup_size);
fw_cfg_add_bytes(fw_cfg, FW_CFG_SETUP_DATA, setup, setup_size);
+ kernel_loader_context.setup_data = (char *)setup;
+ kernel_loader_context.setup_size = setup_size;
+
+ if (sev_enabled()) {
+ sev_add_kernel_loader_hashes(&kernel_loader_context, &error_fatal);
+ }
option_rom[nb_option_roms].bootindex = 0;
option_rom[nb_option_roms].name = "linuxboot.bin";
--
2.25.1
