On 26.04.2013, at 08:51, Bhushan Bharat-R65777 wrote: > > >> -----Original Message----- >> From: Alexander Graf [mailto:ag...@suse.de] >> Sent: Friday, April 26, 2013 11:51 AM >> To: Bhushan Bharat-R65777 >> Cc: qemu-...@nongnu.org; qemu-devel@nongnu.org; Wood Scott-B07421; Bhushan >> Bharat-R65777; Yoder Stuart-B08248 >> Subject: Re: [PATCH] ppc: initialize GPRs as per epapr >> >> >> On 26.04.2013, at 08:17, Bharat Bhushan wrote: >> >>> ePAPR defines the initial values of cpu registers. This patch >>> initialize the GPRs as per ePAPR specification. >>> >>> This resolves the issue of guest reboot/reset (guest hang on reboot). >> >> Why does it hang only on reboot, not on initial bootup? > > may be memory pointed by env pointer are zero initialized initially. > Reboot also not always hangs. I have seen reboot mostly working on > e500v2/e500mc and mostly hanging on e5500.
Yes, they're all zero initialized. I'm surprised that got things working. > >> >>> >>> Signed-off-by: Bharat Bhushan <bharat.bhus...@freescale.com> >>> Signed-off-by: Stuart Yoder <stuart.yo...@freescale.com> >>> --- >>> hw/ppc/e500.c | 7 +++++++ >>> 1 files changed, 7 insertions(+), 0 deletions(-) >>> >>> diff --git a/hw/ppc/e500.c b/hw/ppc/e500.c index c1bdb6b..a47f976 >>> 100644 >>> --- a/hw/ppc/e500.c >>> +++ b/hw/ppc/e500.c >>> @@ -37,6 +37,7 @@ >>> #include "qemu/host-utils.h" >>> #include "hw/pci-host/ppce500.h" >>> >>> +#define EPAPR_MAGIC (0x45504150) >>> #define BINARY_DEVICE_TREE_FILE "mpc8544ds.dtb" >>> #define UIMAGE_LOAD_BASE 0 >>> #define DTC_LOAD_PAD 0x1800000 >>> @@ -444,6 +445,12 @@ static void ppce500_cpu_reset(void *opaque) >> >> Does ePAPR mention anything wrt GPR state of secondary CPUs? > > Yes, I think we handle this in hw/ppc/ppce500_spin.c > >> >>> cs->halted = 0; >>> env->gpr[1] = (16<<20) - 8; >>> env->gpr[3] = bi->dt_base; >>> + env->gpr[4] = 0; >>> + env->gpr[5] = 0; >>> + env->gpr[6] = EPAPR_MAGIC; >>> + env->gpr[7] = (64 * 1024 * 1024); >> >> What is this? > > Size of initial TLB ( should be big enough to cover kernel handler). I do not > see ePAPR defines any value, I set this to 64M. It's dynamic. Please set it to the actual size of the initial TLB mapping we create. Alex