On 22/07/2020 18:57, Srinivas Bangalore wrote:
Dear Xen experts,
Hello,
Would greatly appreciate some hints on how to move forward with this one…
From your first set of original log:
> Xen version 4.8.5 (srinivas@) (aarch64-linux-gnu-gcc
> (Ubuntu/Linaro 7.5.0-3ubuntu1~18.04) 7.5.0) debug=n Sun Jul 19 07:44:00
> PDT 2020
I would recommend to compile Xen with debug enabled (CONFIG_DEBUG=y) as
it may provide you more information of what's happening.
Also, aside the Tegra series. Do you have any other patches on top?
[...]
(XEN) BANK[0] 0x000000a0000000-0x000000c0000000 (512MB)
(XEN) Grant table range: 0x000000fec00000-0x000000fec60000
(XEN) Loading zImage from 00000000e1000000 to
00000000a0080000-00000000a223c808
(XEN) Allocating PPI 16 for event channel interrupt
(XEN) Loading dom0 DTB to 0x00000000a8000000-0x00000000a803435c
[...]
(XEN) *** Dumping CPU0 guest state (d0v0): ***
(XEN) ----[ Xen-4.8.5 arm64 debug=n Tainted: C ]----
(XEN) CPU: 0
(XEN) PC: 00000000a0080000
PC is pointing to the entry point of your kernel...
(XEN) LR: 0000000000000000
(XEN) SP_EL0: 0000000000000000
(XEN) SP_EL1: 0000000000000000
(XEN) CPSR: 000001c5 MODE:64-bit EL1h (Guest Kernel, handler)
(XEN) X0: 00000000a8000000 X1: 0000000000000000 X2: 0000000000000000
(XEN) X3: 0000000000000000 X4: 0000000000000000 X5: 0000000000000000
(XEN) X6: 0000000000000000 X7: 0000000000000000 X8: 0000000000000000
(XEN) X9: 0000000000000000 X10: 0000000000000000 X11: 0000000000000000
(XEN) X12: 0000000000000000 X13: 0000000000000000 X14: 0000000000000000
(XEN) X15: 0000000000000000 X16: 0000000000000000 X17: 0000000000000000
(XEN) X18: 0000000000000000 X19: 0000000000000000 X20: 0000000000000000
(XEN) X21: 0000000000000000 X22: 0000000000000000 X23: 0000000000000000
(XEN) X24: 0000000000000000 X25: 0000000000000000 X26: 0000000000000000
(XEN) X27: 0000000000000000 X28: 0000000000000000 FP: 0000000000000000
(XEN)
(XEN) ELR_EL1: 0000000000000000
(XEN) ESR_EL1: 00000000
(XEN) FAR_EL1: 0000000000000000
(XEN)
(XEN) SCTLR_EL1: 00c50838
(XEN) TCR_EL1: 00000000
(XEN) TTBR0_EL1: 0000000000000000
(XEN) TTBR1_EL1: 0000000000000000
(XEN)
(XEN) VTCR_EL2: 80043594
(XEN) VTTBR_EL2: 000100017f0f9000
(XEN)
(XEN) SCTLR_EL2: 30cd183d
(XEN) HCR_EL2: 000000008038663f
(XEN) TTBR0_EL2: 00000000fecfc000
(XEN)
(XEN) ESR_EL2: 8200000d
... it looks like we are receiving a trap in EL2 because it can't
execute the instruction. This is a bit odd as the p2m (stage-2
page-tables) should be configured to allow execution. It would be useful
if you can dump the p2m walk here. This following patch should do the
job (not compiled test):
diff --git a/xen/arch/arm/traps.c b/xen/arch/arm/traps.c
index d578a5c598dd..af1834cdf735 100644
--- a/xen/arch/arm/traps.c
+++ b/xen/arch/arm/traps.c
@@ -2489,9 +2489,14 @@ static void do_trap_instr_abort_guest(struct
cpu_user_regs *regs,
*/
rc = gva_to_ipa(gva, &gpa, GV2M_READ);
if ( rc == -EFAULT )
+ {
+ printk("Unable to translate 0x%lx\n", gva);
return; /* Try again */
+ }
}
+ dump_p2m_walk(current->domain, gpa);
+
switch ( fsc )
{
case FSC_FLT_PERM:
(XEN) HPFAR_EL2: 0000000000000000
(XEN) FAR_EL2: 00000000a0080000
(XEN)
(XEN) Guest stack trace from sp=0:
(XEN) Failed to convert stack to physical address
[...]
It seems the DOM0 kernel did not get added to the task list….
From a look at the dump, dom0 vCPU0 has been scheduled and running on
pCPU0.
Boot args for Xen and Dom0 are here:
(XEN) Checking for initrd in /chosen
(XEN) linux,initrd limits invalid: 0000000084100000 >= 0000000084100000
(XEN) RAM: 0000000080000000 - 00000000fedfffff
(XEN) RAM: 0000000100000000 - 000000017f1fffff
(XEN)
(XEN) MODULE[0]: 00000000fc7f8000 - 00000000fc82d000 Device Tree
(XEN) MODULE[1]: 00000000e1000000 - 00000000e31bc808 Kernel
console=hvc0 earlyprintk=xen earlycon=xen rootfstype=ext4 rw rootwait
root=/dev/mmcblk0p1 rdinit=/sbin/init
You want to use earlycon=xenboot here.
(XEN) RESVD[0]: 0000000080000000 - 0000000080020000
(XEN) RESVD[1]: 00000000e3500000 - 00000000e3535000
(XEN) RESVD[2]: 00000000fc7f8000 - 00000000fc82d000
(XEN)
(XEN) Command line: console=dtuart earlyprintk=xen
earlycon=uart8250,mmio32,0x70006000 sync_console dom0_mem=512M
log_lvl=all guest_loglvl=all console_to_ring
FWIW, earlyprintk and earlycon are not understood by Xen. They are only
useful for Dom0.
Best regards,
--
Julien Grall
