On 12.06.2018 12:04, Christian Borntraeger wrote:
> Right now the IPL device always starts from address 0x10000 (the usual
> Linux entry point). To run other guests (e.g. test programs) it is
> useful to use the IPL PSW from address 0. We can use the Linux magic
> at 0x10008 to decide.
>
> Signed-off-by: Christian Borntraeger <borntrae...@de.ibm.com>
> ---
> v2->v3:
> - check for iplpsw to avoid assert on file errors
> - use 4 bytes at 4 instead of 8 bytes at 0
I trust you that this is the right thing to do :)
Reviewed-by: David Hildenbrand <da...@redhat.com>
> v1->v2:
> - use LINUX_MAGIC_ADDR define
> - use assert for valid iplpsw pointer
> - add endianess conversion
> hw/s390x/ipl.c | 19 ++++++++++++++++++-
> 1 file changed, 18 insertions(+), 1 deletion(-)
>
> diff --git a/hw/s390x/ipl.c b/hw/s390x/ipl.c
> index 04245b5258..1a42630962 100644
> --- a/hw/s390x/ipl.c
> +++ b/hw/s390x/ipl.c
> @@ -29,6 +29,7 @@
> #include "exec/exec-all.h"
>
> #define KERN_IMAGE_START 0x010000UL
> +#define LINUX_MAGIC_ADDR 0x010008UL
> #define KERN_PARM_AREA 0x010480UL
> #define INITRD_START 0x800000UL
> #define INITRD_PARM_START 0x010408UL
> @@ -105,7 +106,9 @@ static uint64_t bios_translate_addr(void *opaque,
> uint64_t srcaddr)
> static void s390_ipl_realize(DeviceState *dev, Error **errp)
> {
> S390IPLState *ipl = S390_IPL(dev);
> - uint64_t pentry = KERN_IMAGE_START;
> + uint32_t *iplpsw;
> + uint64_t pentry;
> + char *magic;
> int kernel_size;
> Error *err = NULL;
>
> @@ -157,6 +160,20 @@ static void s390_ipl_realize(DeviceState *dev, Error
> **errp)
> NULL, 1, EM_S390, 0, 0);
> if (kernel_size < 0) {
> kernel_size = load_image_targphys(ipl->kernel, 0, ram_size);
> + /* if this is Linux use KERN_IMAGE_START */
> + magic = rom_ptr(LINUX_MAGIC_ADDR);
> + if (magic && !memcmp(magic, "S390EP", 6)) {
> + pentry = KERN_IMAGE_START;
> + } else {
> + /* if not Linux use the IPL PSW */
> + iplpsw = rom_ptr(4);
> + if (iplpsw) {
> + pentry = be32_to_cpu(*iplpsw) & 0x7fffffffUL;
> + } else {
> + error_setg(&err, "Could not get IPL PSW");
> + goto error;
> + }
> + }
> }
> if (kernel_size < 0) {
> error_setg(&err, "could not load kernel '%s'", ipl->kernel);
>
--
Thanks,
David / dhildenb
