On Tue, Sep 13, 2016 at 10:50:24AM -0400, Brijesh Singh wrote:
> In SEV-enabled mode we need to reload the BIOS image on loader reset, this
> will ensure that BIOS image gets encrypted and included as part of launch
> meausrement on guest reset.
>
> Signed-off-by: Brijesh Singh <brijesh.si...@amd.com>
Could you pls explain what does measurement mean in this
context, and how is it helpful to reload rom on
every boot as opposed to first boot after migration?
> ---
> hw/core/loader.c | 7 ++++++-
> 1 file changed, 6 insertions(+), 1 deletion(-)
>
> diff --git a/hw/core/loader.c b/hw/core/loader.c
> index 53e0e41..9b03bfe 100644
> --- a/hw/core/loader.c
> +++ b/hw/core/loader.c
> @@ -55,6 +55,7 @@
> #include "exec/address-spaces.h"
> #include "hw/boards.h"
> #include "qemu/cutils.h"
> +#include "sysemu/kvm.h"
>
> #include <zlib.h>
>
> @@ -1011,7 +1012,11 @@ static void rom_reset(void *unused)
> cpu_physical_memory_write_rom(&address_space_memory,
> rom->addr, rom->data,
> rom->datasize);
> }
> - if (rom->isrom) {
> +
> + /* reload the rom on SEV-enabled guest so that it gets included into
> + * guest memory measurement on system reset.
> + */
> + if (!kvm_sev_enabled() && rom->isrom) {
> /* rom needs to be written only once */
> g_free(rom->data);
> rom->data = NULL;
