From 96e39ac0e9d18020c8c5a41b64b8fe86c26575ab Mon Sep 17 00:00:00 2001 From: Jason Wang Date: Thu, 25 Jul 2013 16:54:32 +0800 Subject: x86: Introduce hypervisor_cpuid_base() This patch introduce hypervisor_cpuid_base() which loop test the hypervisor existence function until the signature match and check the number of leaves if required. This could be used by Xen/KVM guest to detect the existence of hypervisor. Cc: Paolo Bonzini Cc: Gleb Natapov Signed-off-by: Jason Wang Link: http://lkml.kernel.org/r/1374742475-2485-1-git-send-email-jasowang@redhat.com Signed-off-by: H. Peter Anvin diff --git a/arch/x86/include/asm/processor.h b/arch/x86/include/asm/processor.h index 24cf5ae..7763307 100644 --- a/arch/x86/include/asm/processor.h +++ b/arch/x86/include/asm/processor.h @@ -971,6 +971,21 @@ unsigned long calc_aperfmperf_ratio(struct aperfmperf *old, return ratio; } +static inline uint32_t hypervisor_cpuid_base(const char *sig, uint32_t leaves) +{ + uint32_t base, eax, signature[3]; + + for (base = 0x40000000; base < 0x40010000; base += 0x100) { + cpuid(base, &eax, &signature[0], &signature[1], &signature[2]); + + if (!memcmp(sig, signature, 12) && + (leaves == 0 || ((eax - base) >= leaves))) + return base; + } + + return 0; +} + extern unsigned long arch_align_stack(unsigned long sp); extern void free_init_pages(char *what, unsigned long begin, unsigned long end); -- cgit v0.10.2 From 448ac44d561f0aba5baac54bac62fe40d07230b6 Mon Sep 17 00:00:00 2001 From: Jason Wang Date: Thu, 25 Jul 2013 16:54:33 +0800 Subject: xen: Switch to use hypervisor_cpuid_base() Switch to use hypervisor_cpuid_base() to detect Xen. Cc: Konrad Rzeszutek Wilk Cc: Jeremy Fitzhardinge Cc: Paolo Bonzini Signed-off-by: Jason Wang Link: http://lkml.kernel.org/r/1374742475-2485-2-git-send-email-jasowang@redhat.com Signed-off-by: H. Peter Anvin diff --git a/arch/x86/include/asm/xen/hypervisor.h b/arch/x86/include/asm/xen/hypervisor.h index 125f344..d866959 100644 --- a/arch/x86/include/asm/xen/hypervisor.h +++ b/arch/x86/include/asm/xen/hypervisor.h @@ -40,21 +40,7 @@ extern struct start_info *xen_start_info; static inline uint32_t xen_cpuid_base(void) { - uint32_t base, eax, ebx, ecx, edx; - char signature[13]; - - for (base = 0x40000000; base < 0x40010000; base += 0x100) { - cpuid(base, &eax, &ebx, &ecx, &edx); - *(uint32_t *)(signature + 0) = ebx; - *(uint32_t *)(signature + 4) = ecx; - *(uint32_t *)(signature + 8) = edx; - signature[12] = 0; - - if (!strcmp("XenVMMXenVMM", signature) && ((eax - base) >= 2)) - return base; - } - - return 0; + return hypervisor_cpuid_base("XenVMMXenVMM", 2); } #ifdef CONFIG_XEN -- cgit v0.10.2 From 1085ba7f552d84aa8ac0ae903fa8d0cc2ff9f79d Mon Sep 17 00:00:00 2001 From: Jason Wang Date: Thu, 25 Jul 2013 16:54:34 +0800 Subject: x86, kvm: Switch to use hypervisor_cpuid_base() Switch to use hypervisor_cpuid_base() to detect KVM. Cc: Gleb Natapov Cc: Paolo Bonzini Signed-off-by: Jason Wang Link: http://lkml.kernel.org/r/1374742475-2485-3-git-send-email-jasowang@redhat.com Signed-off-by: H. Peter Anvin diff --git a/arch/x86/include/asm/kvm_para.h b/arch/x86/include/asm/kvm_para.h index 695399f..0644129 100644 --- a/arch/x86/include/asm/kvm_para.h +++ b/arch/x86/include/asm/kvm_para.h @@ -85,26 +85,20 @@ static inline long kvm_hypercall4(unsigned int nr, unsigned long p1, return ret; } -static inline bool kvm_para_available(void) +static inline uint32_t kvm_cpuid_base(void) { - unsigned int eax, ebx, ecx, edx; - char signature[13]; - if (boot_cpu_data.cpuid_level < 0) - return false; /* So we don't blow up on old processors */ + return 0; /* So we don't blow up on old processors */ - if (cpu_has_hypervisor) { - cpuid(KVM_CPUID_SIGNATURE, &eax, &ebx, &ecx, &edx); - memcpy(signature + 0, &ebx, 4); - memcpy(signature + 4, &ecx, 4); - memcpy(signature + 8, &edx, 4); - signature[12] = 0; + if (cpu_has_hypervisor) + return hypervisor_cpuid_base("KVMKVMKVM\0\0\0", 0); - if (strcmp(signature, "KVMKVMKVM") == 0) - return true; - } + return 0; +} - return false; +static inline bool kvm_para_available(void) +{ + return kvm_cpuid_base() != 0; } static inline unsigned int kvm_arch_para_features(void) -- cgit v0.10.2 From 9df56f19a500bea90d160be1bf77e4fbcd204d3f Mon Sep 17 00:00:00 2001 From: Jason Wang Date: Thu, 25 Jul 2013 16:54:35 +0800 Subject: x86: Correctly detect hypervisor We try to handle the hypervisor compatibility mode by detecting hypervisor through a specific order. This is not robust, since hypervisors may implement each others features. This patch tries to handle this situation by always choosing the last one in the CPUID leaves. This is done by letting .detect() return a priority instead of true/false and just re-using the CPUID leaf where the signature were found as the priority (or 1 if it was found by DMI). Then we can just pick hypervisor who has the highest priority. Other sophisticated detection method could also be implemented on top. Suggested by H. Peter Anvin and Paolo Bonzini. Acked-by: K. Y. Srinivasan Cc: Haiyang Zhang Cc: Konrad Rzeszutek Wilk Cc: Jeremy Fitzhardinge Cc: Doug Covelli Cc: Borislav Petkov Cc: Dan Hecht Cc: Paul Gortmaker Cc: Marcelo Tosatti Cc: Gleb Natapov Cc: Paolo Bonzini Cc: Frederic Weisbecker Signed-off-by: Jason Wang Link: http://lkml.kernel.org/r/1374742475-2485-4-git-send-email-jasowang@redhat.com Signed-off-by: H. Peter Anvin diff --git a/arch/x86/include/asm/hypervisor.h b/arch/x86/include/asm/hypervisor.h index 2d4b5e6..e42f758 100644 --- a/arch/x86/include/asm/hypervisor.h +++ b/arch/x86/include/asm/hypervisor.h @@ -33,7 +33,7 @@ struct hypervisor_x86 { const char *name; /* Detection routine */ - bool (*detect)(void); + uint32_t (*detect)(void); /* Adjust CPU feature bits (run once per CPU) */ void (*set_cpu_features)(struct cpuinfo_x86 *); diff --git a/arch/x86/kernel/cpu/hypervisor.c b/arch/x86/kernel/cpu/hypervisor.c index 8727921..36ce402 100644 --- a/arch/x86/kernel/cpu/hypervisor.c +++ b/arch/x86/kernel/cpu/hypervisor.c @@ -25,11 +25,6 @@ #include #include -/* - * Hypervisor detect order. This is specified explicitly here because - * some hypervisors might implement compatibility modes for other - * hypervisors and therefore need to be detected in specific sequence. - */ static const __initconst struct hypervisor_x86 * const hypervisors[] = { #ifdef CONFIG_XEN_PVHVM @@ -49,15 +44,19 @@ static inline void __init detect_hypervisor_vendor(void) { const struct hypervisor_x86 *h, * const *p; + uint32_t pri, max_pri = 0; for (p = hypervisors; p < hypervisors + ARRAY_SIZE(hypervisors); p++) { h = *p; - if (h->detect()) { + pri = h->detect(); + if (pri != 0 && pri > max_pri) { + max_pri = pri; x86_hyper = h; - printk(KERN_INFO "Hypervisor detected: %s\n", h->name); - break; } } + + if (max_pri) + printk(KERN_INFO "Hypervisor detected: %s\n", x86_hyper->name); } void init_hypervisor(struct cpuinfo_x86 *c) diff --git a/arch/x86/kernel/cpu/mshyperv.c b/arch/x86/kernel/cpu/mshyperv.c index 8f4be53..71a39f3 100644 --- a/arch/x86/kernel/cpu/mshyperv.c +++ b/arch/x86/kernel/cpu/mshyperv.c @@ -27,20 +27,23 @@ struct ms_hyperv_info ms_hyperv; EXPORT_SYMBOL_GPL(ms_hyperv); -static bool __init ms_hyperv_platform(void) +static uint32_t __init ms_hyperv_platform(void) { u32 eax; u32 hyp_signature[3]; if (!boot_cpu_has(X86_FEATURE_HYPERVISOR)) - return false; + return 0; cpuid(HYPERV_CPUID_VENDOR_AND_MAX_FUNCTIONS, &eax, &hyp_signature[0], &hyp_signature[1], &hyp_signature[2]); - return eax >= HYPERV_CPUID_MIN && - eax <= HYPERV_CPUID_MAX && - !memcmp("Microsoft Hv", hyp_signature, 12); + if (eax >= HYPERV_CPUID_MIN && + eax <= HYPERV_CPUID_MAX && + !memcmp("Microsoft Hv", hyp_signature, 12)) + return HYPERV_CPUID_VENDOR_AND_MAX_FUNCTIONS; + + return 0; } static cycle_t read_hv_clock(struct clocksource *arg) diff --git a/arch/x86/kernel/cpu/vmware.c b/arch/x86/kernel/cpu/vmware.c index 7076878..628a059 100644 --- a/arch/x86/kernel/cpu/vmware.c +++ b/arch/x86/kernel/cpu/vmware.c @@ -93,7 +93,7 @@ static void __init vmware_platform_setup(void) * serial key should be enough, as this will always have a VMware * specific string when running under VMware hypervisor. */ -static bool __init vmware_platform(void) +static uint32_t __init vmware_platform(void) { if (cpu_has_hypervisor) { unsigned int eax; @@ -102,12 +102,12 @@ static bool __init vmware_platform(void) cpuid(CPUID_VMWARE_INFO_LEAF, &eax, &hyper_vendor_id[0], &hyper_vendor_id[1], &hyper_vendor_id[2]); if (!memcmp(hyper_vendor_id, "VMwareVMware", 12)) - return true; + return CPUID_VMWARE_INFO_LEAF; } else if (dmi_available && dmi_name_in_serial("VMware") && __vmware_platform()) - return true; + return 1; - return false; + return 0; } /* diff --git a/arch/x86/kernel/kvm.c b/arch/x86/kernel/kvm.c index a96d32c..7817afd 100644 --- a/arch/x86/kernel/kvm.c +++ b/arch/x86/kernel/kvm.c @@ -498,11 +498,9 @@ void __init kvm_guest_init(void) #endif } -static bool __init kvm_detect(void) +static uint32_t __init kvm_detect(void) { - if (!kvm_para_available()) - return false; - return true; + return kvm_cpuid_base(); } const struct hypervisor_x86 x86_hyper_kvm __refconst = { diff --git a/arch/x86/xen/enlighten.c b/arch/x86/xen/enlighten.c index 193097e..2fcaedc 100644 --- a/arch/x86/xen/enlighten.c +++ b/arch/x86/xen/enlighten.c @@ -1720,15 +1720,12 @@ static void __init xen_hvm_guest_init(void) xen_hvm_init_mmu_ops(); } -static bool __init xen_hvm_platform(void) +static uint32_t __init xen_hvm_platform(void) { if (xen_pv_domain()) - return false; - - if (!xen_cpuid_base()) - return false; + return 0; - return true; + return xen_cpuid_base(); } bool xen_hvm_need_lapic(void) -- cgit v0.10.2