From 2b953a5e994ce279904ec70220f7d4f31d380a0a Mon Sep 17 00:00:00 2001 From: Boris Ostrovsky Date: Tue, 28 Apr 2015 18:46:20 -0400 Subject: xen: Suspend ticks on all CPUs during suspend Commit 77e32c89a711 ("clockevents: Manage device's state separately for the core") decouples clockevent device's modes from states. With this change when a Xen guest tries to resume, it won't be calling its set_mode op which needs to be done on each VCPU in order to make the hypervisor aware that we are in oneshot mode. This happens because clockevents_tick_resume() (which is an intermediate step of resuming ticks on a processor) doesn't call clockevents_set_state() anymore and because during suspend clockevent devices on all VCPUs (except for the one doing the suspend) are left in ONESHOT state. As result, during resume the clockevents state machine will assume that device is already where it should be and doesn't need to be updated. To avoid this problem we should suspend ticks on all VCPUs during suspend. Signed-off-by: Boris Ostrovsky Signed-off-by: David Vrabel --- arch/x86/xen/suspend.c | 10 ++++++++++ 1 file changed, 10 insertions(+) (limited to 'arch') diff --git a/arch/x86/xen/suspend.c b/arch/x86/xen/suspend.c index d9497698645a..53b4c0811f4f 100644 --- a/arch/x86/xen/suspend.c +++ b/arch/x86/xen/suspend.c @@ -88,7 +88,17 @@ static void xen_vcpu_notify_restore(void *data) tick_resume_local(); } +static void xen_vcpu_notify_suspend(void *data) +{ + tick_suspend_local(); +} + void xen_arch_resume(void) { on_each_cpu(xen_vcpu_notify_restore, NULL, 1); } + +void xen_arch_suspend(void) +{ + on_each_cpu(xen_vcpu_notify_suspend, NULL, 1); +} -- cgit 1.4.1 From a71dbdaa8ca2933391b08e0ae5567083e3af0892 Mon Sep 17 00:00:00 2001 From: Boris Ostrovsky Date: Mon, 4 May 2015 11:02:15 -0400 Subject: hypervisor/x86/xen: Unset X86_BUG_SYSRET_SS_ATTRS on Xen PV guests Commit 61f01dd941ba ("x86_64, asm: Work around AMD SYSRET SS descriptor attribute issue") makes AMD processors set SS to __KERNEL_DS in __switch_to() to deal with cases when SS is NULL. This breaks Xen PV guests who do not want to load SS with__KERNEL_DS. Since the problem that the commit is trying to address would have to be fixed in the hypervisor (if it in fact exists under Xen) there is no reason to set X86_BUG_SYSRET_SS_ATTRS flag for PV VPCUs here. This can be easily achieved by adding x86_hyper_xen_hvm.set_cpu_features op which will clear this flag. (And since this structure is no longer HVM-specific we should do some renaming). Signed-off-by: Boris Ostrovsky Reported-by: Sander Eikelenboom Signed-off-by: David Vrabel --- arch/x86/include/asm/hypervisor.h | 2 +- arch/x86/kernel/cpu/hypervisor.c | 4 ++-- arch/x86/xen/enlighten.c | 27 ++++++++++++++++++--------- 3 files changed, 21 insertions(+), 12 deletions(-) (limited to 'arch') diff --git a/arch/x86/include/asm/hypervisor.h b/arch/x86/include/asm/hypervisor.h index e42f758a0fbd..055ea9941dd5 100644 --- a/arch/x86/include/asm/hypervisor.h +++ b/arch/x86/include/asm/hypervisor.h @@ -50,7 +50,7 @@ extern const struct hypervisor_x86 *x86_hyper; /* Recognized hypervisors */ extern const struct hypervisor_x86 x86_hyper_vmware; extern const struct hypervisor_x86 x86_hyper_ms_hyperv; -extern const struct hypervisor_x86 x86_hyper_xen_hvm; +extern const struct hypervisor_x86 x86_hyper_xen; extern const struct hypervisor_x86 x86_hyper_kvm; extern void init_hypervisor(struct cpuinfo_x86 *c); diff --git a/arch/x86/kernel/cpu/hypervisor.c b/arch/x86/kernel/cpu/hypervisor.c index 36ce402a3fa5..d820d8eae96b 100644 --- a/arch/x86/kernel/cpu/hypervisor.c +++ b/arch/x86/kernel/cpu/hypervisor.c @@ -27,8 +27,8 @@ static const __initconst struct hypervisor_x86 * const hypervisors[] = { -#ifdef CONFIG_XEN_PVHVM - &x86_hyper_xen_hvm, +#ifdef CONFIG_XEN + &x86_hyper_xen, #endif &x86_hyper_vmware, &x86_hyper_ms_hyperv, diff --git a/arch/x86/xen/enlighten.c b/arch/x86/xen/enlighten.c index 94578efd3067..46957ead3060 100644 --- a/arch/x86/xen/enlighten.c +++ b/arch/x86/xen/enlighten.c @@ -1760,6 +1760,9 @@ static struct notifier_block xen_hvm_cpu_notifier = { static void __init xen_hvm_guest_init(void) { + if (xen_pv_domain()) + return; + init_hvm_pv_info(); xen_hvm_init_shared_info(); @@ -1775,6 +1778,7 @@ static void __init xen_hvm_guest_init(void) xen_hvm_init_time_ops(); xen_hvm_init_mmu_ops(); } +#endif static bool xen_nopv = false; static __init int xen_parse_nopv(char *arg) @@ -1784,14 +1788,11 @@ static __init int xen_parse_nopv(char *arg) } early_param("xen_nopv", xen_parse_nopv); -static uint32_t __init xen_hvm_platform(void) +static uint32_t __init xen_platform(void) { if (xen_nopv) return 0; - if (xen_pv_domain()) - return 0; - return xen_cpuid_base(); } @@ -1809,11 +1810,19 @@ bool xen_hvm_need_lapic(void) } EXPORT_SYMBOL_GPL(xen_hvm_need_lapic); -const struct hypervisor_x86 x86_hyper_xen_hvm __refconst = { - .name = "Xen HVM", - .detect = xen_hvm_platform, +static void xen_set_cpu_features(struct cpuinfo_x86 *c) +{ + if (xen_pv_domain()) + clear_cpu_bug(c, X86_BUG_SYSRET_SS_ATTRS); +} + +const struct hypervisor_x86 x86_hyper_xen = { + .name = "Xen", + .detect = xen_platform, +#ifdef CONFIG_XEN_PVHVM .init_platform = xen_hvm_guest_init, +#endif .x2apic_available = xen_x2apic_para_available, + .set_cpu_features = xen_set_cpu_features, }; -EXPORT_SYMBOL(x86_hyper_xen_hvm); -#endif +EXPORT_SYMBOL(x86_hyper_xen); -- cgit 1.4.1 From 8746515d7f04c9ea94cf43e2db1fd2cfca93276d Mon Sep 17 00:00:00 2001 From: Stefano Stabellini Date: Fri, 24 Apr 2015 10:16:40 +0100 Subject: xen: Add __GFP_DMA flag when xen_swiotlb_init gets free pages on ARM Make sure that xen_swiotlb_init allocates buffers that are DMA capable when at least one memblock is available below 4G. Otherwise we assume that all devices on the SoC can cope with >4G addresses. We do this on ARM and ARM64, where dom0 is mapped 1:1, so pfn == mfn in this case. No functional changes on x86. From: Chen Baozi Signed-off-by: Chen Baozi Signed-off-by: Stefano Stabellini Tested-by: Chen Baozi Acked-by: Konrad Rzeszutek Wilk Signed-off-by: David Vrabel --- arch/arm/include/asm/xen/page.h | 1 + arch/arm/xen/mm.c | 15 +++++++++++++++ arch/x86/include/asm/xen/page.h | 5 +++++ drivers/xen/swiotlb-xen.c | 2 +- 4 files changed, 22 insertions(+), 1 deletion(-) (limited to 'arch') diff --git a/arch/arm/include/asm/xen/page.h b/arch/arm/include/asm/xen/page.h index 2f7e6ff67d51..0b579b2f4e0e 100644 --- a/arch/arm/include/asm/xen/page.h +++ b/arch/arm/include/asm/xen/page.h @@ -110,5 +110,6 @@ static inline bool set_phys_to_machine(unsigned long pfn, unsigned long mfn) bool xen_arch_need_swiotlb(struct device *dev, unsigned long pfn, unsigned long mfn); +unsigned long xen_get_swiotlb_free_pages(unsigned int order); #endif /* _ASM_ARM_XEN_PAGE_H */ diff --git a/arch/arm/xen/mm.c b/arch/arm/xen/mm.c index 793551d15f1d..498325074a06 100644 --- a/arch/arm/xen/mm.c +++ b/arch/arm/xen/mm.c @@ -4,6 +4,7 @@ #include #include #include +#include #include #include #include @@ -21,6 +22,20 @@ #include #include +unsigned long xen_get_swiotlb_free_pages(unsigned int order) +{ + struct memblock_region *reg; + gfp_t flags = __GFP_NOWARN; + + for_each_memblock(memory, reg) { + if (reg->base < (phys_addr_t)0xffffffff) { + flags |= __GFP_DMA; + break; + } + } + return __get_free_pages(flags, order); +} + enum dma_cache_op { DMA_UNMAP, DMA_MAP, diff --git a/arch/x86/include/asm/xen/page.h b/arch/x86/include/asm/xen/page.h index 358dcd338915..c44a5d53e464 100644 --- a/arch/x86/include/asm/xen/page.h +++ b/arch/x86/include/asm/xen/page.h @@ -269,4 +269,9 @@ static inline bool xen_arch_need_swiotlb(struct device *dev, return false; } +static inline unsigned long xen_get_swiotlb_free_pages(unsigned int order) +{ + return __get_free_pages(__GFP_NOWARN, order); +} + #endif /* _ASM_X86_XEN_PAGE_H */ diff --git a/drivers/xen/swiotlb-xen.c b/drivers/xen/swiotlb-xen.c index 810ad419e34c..4c549323c605 100644 --- a/drivers/xen/swiotlb-xen.c +++ b/drivers/xen/swiotlb-xen.c @@ -235,7 +235,7 @@ retry: #define SLABS_PER_PAGE (1 << (PAGE_SHIFT - IO_TLB_SHIFT)) #define IO_TLB_MIN_SLABS ((1<<20) >> IO_TLB_SHIFT) while ((SLABS_PER_PAGE << order) > IO_TLB_MIN_SLABS) { - xen_io_tlb_start = (void *)__get_free_pages(__GFP_NOWARN, order); + xen_io_tlb_start = (void *)xen_get_swiotlb_free_pages(order); if (xen_io_tlb_start) break; order--; -- cgit 1.4.1