From f221b04fe07eb56c39935e31bb8e9ddacc00612f Mon Sep 17 00:00:00 2001 From: Jan Beulich Date: Tue, 13 Jan 2015 07:40:05 +0000 Subject: x86/xen: properly retrieve NMI reason Using the native code here can't work properly, as the hypervisor would normally have cleared the two reason bits by the time Dom0 gets to see the NMI (if passed to it at all). There's a shared info field for this, and there's an existing hook to use - just fit the two together. This is particularly relevant so that NMIs intended to be handled by APEI / GHES actually make it to the respective handler. Note that the hook can (and should) be used irrespective of whether being in Dom0, as accessing port 0x61 in a DomU would be even worse, while the shared info field would just hold zero all the time. Note further that hardware NMI handling for PVH doesn't currently work anyway due to missing code in the hypervisor (but it is expected to work the native rather than the PV way). Signed-off-by: Jan Beulich Reviewed-by: Boris Ostrovsky Signed-off-by: David Vrabel --- arch/x86/xen/enlighten.c | 22 +++++++++++++++++++++- 1 file changed, 21 insertions(+), 1 deletion(-) (limited to 'arch/x86/xen') diff --git a/arch/x86/xen/enlighten.c b/arch/x86/xen/enlighten.c index fac5e4f9607c..115016347806 100644 --- a/arch/x86/xen/enlighten.c +++ b/arch/x86/xen/enlighten.c @@ -40,6 +40,7 @@ #include #include #include +#include #include #include #include @@ -66,6 +67,7 @@ #include #include #include +#include #include #include #include @@ -1357,6 +1359,21 @@ static const struct machine_ops xen_machine_ops __initconst = { .emergency_restart = xen_emergency_restart, }; +static unsigned char xen_get_nmi_reason(void) +{ + unsigned char reason = 0; + + /* Construct a value which looks like it came from port 0x61. */ + if (test_bit(_XEN_NMIREASON_io_error, + &HYPERVISOR_shared_info->arch.nmi_reason)) + reason |= NMI_REASON_IOCHK; + if (test_bit(_XEN_NMIREASON_pci_serr, + &HYPERVISOR_shared_info->arch.nmi_reason)) + reason |= NMI_REASON_SERR; + + return reason; +} + static void __init xen_boot_params_init_edd(void) { #if IS_ENABLED(CONFIG_EDD) @@ -1541,9 +1558,12 @@ asmlinkage __visible void __init xen_start_kernel(void) pv_info = xen_info; pv_init_ops = xen_init_ops; pv_apic_ops = xen_apic_ops; - if (!xen_pvh_domain()) + if (!xen_pvh_domain()) { pv_cpu_ops = xen_cpu_ops; + x86_platform.get_nmi_reason = xen_get_nmi_reason; + } + if (xen_feature(XENFEAT_auto_translated_physmap)) x86_init.resources.memory_setup = xen_auto_xlated_memory_setup; else -- cgit v1.2.2