From 6efa20e49b9cb1db1ab66870cc37323474a75a13 Mon Sep 17 00:00:00 2001 From: Konrad Rzeszutek Wilk Date: Fri, 19 Jul 2013 11:51:31 -0400 Subject: xen: Support 64-bit PV guest receiving NMIs This is based on a patch that Zhenzhong Duan had sent - which was missing some of the remaining pieces. The kernel has the logic to handle Xen-type-exceptions using the paravirt interface in the assembler code (see PARAVIRT_ADJUST_EXCEPTION_FRAME - pv_irq_ops.adjust_exception_frame and and INTERRUPT_RETURN - pv_cpu_ops.iret). That means the nmi handler (and other exception handlers) use the hypervisor iret. The other changes that would be neccessary for this would be to translate the NMI_VECTOR to one of the entries on the ipi_vector and make xen_send_IPI_mask_allbutself use different events. Fortunately for us commit 1db01b4903639fcfaec213701a494fe3fb2c490b (xen: Clean up apic ipi interface) implemented this and we piggyback on the cleanup such that the apic IPI interface will pass the right vector value for NMI. With this patch we can trigger NMIs within a PV guest (only tested x86_64). For this to work with normal PV guests (not initial domain) we need the domain to be able to use the APIC ops - they are already implemented to use the Xen event channels. For that to be turned on in a PV domU we need to remove the masking of X86_FEATURE_APIC. Incidentally that means kgdb will also now work within a PV guest without using the 'nokgdbroundup' workaround. Note that the 32-bit version is different and this patch does not enable that. CC: Lisa Nguyen CC: Ben Guthro CC: Zhenzhong Duan Signed-off-by: Konrad Rzeszutek Wilk [v1: Fixed up per David Vrabel comments] Reviewed-by: Ben Guthro Reviewed-by: David Vrabel --- arch/x86/xen/setup.c | 13 +++++++++++-- 1 file changed, 11 insertions(+), 2 deletions(-) (limited to 'arch/x86/xen/setup.c') diff --git a/arch/x86/xen/setup.c b/arch/x86/xen/setup.c index 056d11faef21..403f5cc5415b 100644 --- a/arch/x86/xen/setup.c +++ b/arch/x86/xen/setup.c @@ -33,6 +33,9 @@ /* These are code, but not functions. Defined in entry.S */ extern const char xen_hypervisor_callback[]; extern const char xen_failsafe_callback[]; +#ifdef CONFIG_X86_64 +extern const char nmi[]; +#endif extern void xen_sysenter_target(void); extern void xen_syscall_target(void); extern void xen_syscall32_target(void); @@ -525,7 +528,13 @@ void xen_enable_syscall(void) } #endif /* CONFIG_X86_64 */ } - +void __cpuinit xen_enable_nmi(void) +{ +#ifdef CONFIG_X86_64 + if (register_callback(CALLBACKTYPE_nmi, nmi)) + BUG(); +#endif +} void __init xen_arch_setup(void) { xen_panic_handler_init(); @@ -543,7 +552,7 @@ void __init xen_arch_setup(void) xen_enable_sysenter(); xen_enable_syscall(); - + xen_enable_nmi(); #ifdef CONFIG_ACPI if (!(xen_start_info->flags & SIF_INITDOMAIN)) { printk(KERN_INFO "ACPI in unprivileged domain disabled\n"); -- cgit v1.2.3 From e201bfcc5c4fe6d58ce2b21fb4f4c2a2f0ab7ab8 Mon Sep 17 00:00:00 2001 From: David Vrabel Date: Mon, 22 Jul 2013 15:29:00 +0100 Subject: x86/xen: during early setup, only 1:1 map the ISA region During early setup, when the reserved regions and MMIO holes are being setup as 1:1 in the p2m, clear any mappings instead of making them 1:1 (execept for the ISA region which is expected to be mapped). This fixes a regression introduced in 3.5 by 83d51ab473dd (xen/setup: update VA mapping when releasing memory during setup) which caused hosts with tboot to fail to boot. tboot marks a region in the e820 map as unusable and the dom0 kernel would attempt to map this region and Xen does not permit unusable regions to be mapped by guests. (XEN) 0000000000000000 - 0000000000060000 (usable) (XEN) 0000000000060000 - 0000000000068000 (reserved) (XEN) 0000000000068000 - 000000000009e000 (usable) (XEN) 0000000000100000 - 0000000000800000 (usable) (XEN) 0000000000800000 - 0000000000972000 (unusable) tboot marked this region as unusable. (XEN) 0000000000972000 - 00000000cf200000 (usable) (XEN) 00000000cf200000 - 00000000cf38f000 (reserved) (XEN) 00000000cf38f000 - 00000000cf3ce000 (ACPI data) (XEN) 00000000cf3ce000 - 00000000d0000000 (reserved) (XEN) 00000000e0000000 - 00000000f0000000 (reserved) (XEN) 00000000fe000000 - 0000000100000000 (reserved) (XEN) 0000000100000000 - 0000000630000000 (usable) Signed-off-by: David Vrabel Signed-off-by: Konrad Rzeszutek Wilk --- arch/x86/xen/setup.c | 16 +++++++++++----- 1 file changed, 11 insertions(+), 5 deletions(-) (limited to 'arch/x86/xen/setup.c') diff --git a/arch/x86/xen/setup.c b/arch/x86/xen/setup.c index 403f5cc5415b..6243651623d5 100644 --- a/arch/x86/xen/setup.c +++ b/arch/x86/xen/setup.c @@ -218,13 +218,19 @@ static void __init xen_set_identity_and_release_chunk( unsigned long pfn; /* - * If the PFNs are currently mapped, the VA mapping also needs - * to be updated to be 1:1. + * If the PFNs are currently mapped, clear the mappings + * (except for the ISA region which must be 1:1 mapped) to + * release the refcounts (in Xen) on the original frames. */ - for (pfn = start_pfn; pfn <= max_pfn_mapped && pfn < end_pfn; pfn++) + for (pfn = start_pfn; pfn <= max_pfn_mapped && pfn < end_pfn; pfn++) { + pte_t pte = __pte_ma(0); + + if (pfn < PFN_UP(ISA_END_ADDRESS)) + pte = mfn_pte(pfn, PAGE_KERNEL_IO); + (void)HYPERVISOR_update_va_mapping( - (unsigned long)__va(pfn << PAGE_SHIFT), - mfn_pte(pfn, PAGE_KERNEL_IO), 0); + (unsigned long)__va(pfn << PAGE_SHIFT), pte, 0); + } if (start_pfn < nr_pages) *released += xen_release_chunk( -- cgit v1.2.3