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author | Konrad Rzeszutek Wilk <konrad.wilk@oracle.com> | 2010-11-16 12:09:59 -0500 |
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committer | Jeremy Fitzhardinge <jeremy.fitzhardinge@citrix.com> | 2010-11-22 12:10:31 -0800 |
commit | ec35a69c467026437519bafcf325a7362e422db9 (patch) | |
tree | 6fbecdd24a347d2abb11bb8ccbc1fb7486090b14 /arch/x86/xen/enlighten.c | |
parent | d2a817130cdc142f1c80a8e60eca824a321926af (diff) | |
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xen: set IO permission early (before early_cpu_init())
This patch is based off "xen dom0: Set up basic IO permissions for dom0."
by Juan Quintela <quintela@redhat.com>.
On AMD machines when we boot the kernel as Domain 0 we get this nasty:
mapping kernel into physical memory
Xen: setup ISA identity maps
about to get started...
(XEN) traps.c:475:d0 Unhandled general protection fault fault/trap [#13] on VCPU 0 [ec=0000]
(XEN) domain_crash_sync called from entry.S
(XEN) Domain 0 (vcpu#0) crashed on cpu#0:
(XEN) ----[ Xen-4.1-101116 x86_64 debug=y Not tainted ]----
(XEN) CPU: 0
(XEN) RIP: e033:[<ffffffff8130271b>]
(XEN) RFLAGS: 0000000000000282 EM: 1 CONTEXT: pv guest
(XEN) rax: 000000008000c068 rbx: ffffffff8186c680 rcx: 0000000000000068
(XEN) rdx: 0000000000000cf8 rsi: 000000000000c000 rdi: 0000000000000000
(XEN) rbp: ffffffff81801e98 rsp: ffffffff81801e50 r8: ffffffff81801eac
(XEN) r9: ffffffff81801ea8 r10: ffffffff81801eb4 r11: 00000000ffffffff
(XEN) r12: ffffffff8186c694 r13: ffffffff81801f90 r14: ffffffffffffffff
(XEN) r15: 0000000000000000 cr0: 000000008005003b cr4: 00000000000006f0
(XEN) cr3: 0000000221803000 cr2: 0000000000000000
(XEN) ds: 0000 es: 0000 fs: 0000 gs: 0000 ss: e02b cs: e033
(XEN) Guest stack trace from rsp=ffffffff81801e50:
RIP points to read_pci_config() function.
The issue is that we don't set IO permissions for the Linux kernel early enough.
The call sequence used to be:
xen_start_kernel()
x86_init.oem.arch_setup = xen_setup_arch;
setup_arch:
- early_cpu_init
- early_init_amd
- read_pci_config
- x86_init.oem.arch_setup [ xen_arch_setup ]
- set IO permissions.
We need to set the IO permissions earlier on, which this patch does.
Acked-by: Jeremy Fitzhardinge <jeremy.fitzhardinge@citrix.com>
Signed-off-by: Konrad Rzeszutek Wilk <konrad.wilk@oracle.com>
Diffstat (limited to 'arch/x86/xen/enlighten.c')
-rw-r--r-- | arch/x86/xen/enlighten.c | 12 |
1 files changed, 11 insertions, 1 deletions
diff --git a/arch/x86/xen/enlighten.c b/arch/x86/xen/enlighten.c index bd35549..7250bef 100644 --- a/arch/x86/xen/enlighten.c +++ b/arch/x86/xen/enlighten.c @@ -1095,6 +1095,8 @@ static void __init xen_setup_stackprotector(void) /* First C function to be called on Xen boot */ asmlinkage void __init xen_start_kernel(void) { + struct physdev_set_iopl set_iopl; + int rc; pgd_t *pgd; if (!xen_start_info) @@ -1209,10 +1211,18 @@ asmlinkage void __init xen_start_kernel(void) #else pv_info.kernel_rpl = 0; #endif - /* set the limit of our address space */ xen_reserve_top(); + /* We used to do this in xen_arch_setup, but that is too late on AMD + * were early_cpu_init (run before ->arch_setup()) calls early_amd_init + * which pokes 0xcf8 port. + */ + set_iopl.iopl = 1; + rc = HYPERVISOR_physdev_op(PHYSDEVOP_set_iopl, &set_iopl); + if (rc != 0) + xen_raw_printk("physdev_op failed %d\n", rc); + #ifdef CONFIG_X86_32 /* set up basic CPUID stuff */ cpu_detect(&new_cpu_data); |