From acd7ef837d8987ad4ef2ab8f8e8c0f13ab413dd5 Mon Sep 17 00:00:00 2001 From: Christian Borntraeger Date: Tue, 12 Jun 2018 14:59:33 +0200 Subject: [PATCH] s390x/ipl: Try to detect Linux vs non Linux for initial IPL PSW 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 Message-Id: <20180612125933.262679-1-borntraeger@de.ibm.com> Reviewed-by: David Hildenbrand Reviewed-by: Thomas Huth Signed-off-by: Cornelia Huck --- hw/s390x/ipl.c | 27 ++++++++++++++++++++++----- 1 file changed, 22 insertions(+), 5 deletions(-) diff --git a/hw/s390x/ipl.c b/hw/s390x/ipl.c index 04245b5258..0d67349004 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 *ipl_psw; + uint64_t pentry; + char *magic; int kernel_size; Error *err = NULL; @@ -157,10 +160,24 @@ 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 (kernel_size < 0) { - error_setg(&err, "could not load kernel '%s'", ipl->kernel); - goto error; + if (kernel_size < 0) { + error_setg(&err, "could not load kernel '%s'", ipl->kernel); + goto error; + } + /* 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 load the address of the (short) IPL PSW */ + ipl_psw = rom_ptr(4); + if (ipl_psw) { + pentry = be32_to_cpu(*ipl_psw) & 0x7fffffffUL; + } else { + error_setg(&err, "Could not get IPL PSW"); + goto error; + } + } } /* * Is it a Linux kernel (starting at 0x10000)? If yes, we fill in the