> -----Original Message----- > From: Jason Wang [mailto:jasowang@xxxxxxxxxx] > Sent: Thursday, July 25, 2013 4:55 AM > To: tglx@xxxxxxxxxxxxx; mingo@xxxxxxxxxx; hpa@xxxxxxxxx; x86@xxxxxxxxxx; > linux-kernel@xxxxxxxxxxxxxxx; pbonzini@xxxxxxxxxx > Cc: kvm@xxxxxxxxxxxxxxx; Jason Wang; KY Srinivasan; Haiyang Zhang; Konrad > Rzeszutek Wilk; Jeremy Fitzhardinge; Doug Covelli; Borislav Petkov; Dan Hecht; > Paul Gortmaker; Marcelo Tosatti; Gleb Natapov; Frederic Weisbecker; > devel@xxxxxxxxxxxxxxxxxxxxxx; xen-devel@xxxxxxxxxxxxxxxxxxx; > virtualization@xxxxxxxxxxxxxxxxxxxxxxxxxx > Subject: [PATCH V2 4/4] 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() returns 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. > > Cc: Thomas Gleixner <tglx@xxxxxxxxxxxxx> > Cc: Ingo Molnar <mingo@xxxxxxxxxx> > Cc: H. Peter Anvin <hpa@xxxxxxxxx> > Cc: x86@xxxxxxxxxx > Cc: K. Y. Srinivasan <kys@xxxxxxxxxxxxx> > Cc: Haiyang Zhang <haiyangz@xxxxxxxxxxxxx> > Cc: Konrad Rzeszutek Wilk <konrad.wilk@xxxxxxxxxx> > Cc: Jeremy Fitzhardinge <jeremy@xxxxxxxx> > Cc: Doug Covelli <dcovelli@xxxxxxxxxx> > Cc: Borislav Petkov <bp@xxxxxxx> > Cc: Dan Hecht <dhecht@xxxxxxxxxx> > Cc: Paul Gortmaker <paul.gortmaker@xxxxxxxxxxxxx> > Cc: Marcelo Tosatti <mtosatti@xxxxxxxxxx> > Cc: Gleb Natapov <gleb@xxxxxxxxxx> > Cc: Paolo Bonzini <pbonzini@xxxxxxxxxx> > Cc: Frederic Weisbecker <fweisbec@xxxxxxxxx> > Cc: linux-kernel@xxxxxxxxxxxxxxx > Cc: devel@xxxxxxxxxxxxxxxxxxxxxx > Cc: kvm@xxxxxxxxxxxxxxx > Cc: xen-devel@xxxxxxxxxxxxxxxxxxx > Cc: virtualization@xxxxxxxxxxxxxxxxxxxxxxxxxx > Signed-off-by: Jason Wang <jasowang@xxxxxxxxxx> Acked-by: K. Y. Srinivasan <kys@xxxxxxxxxxxxx> > --- > arch/x86/include/asm/hypervisor.h | 2 +- > arch/x86/kernel/cpu/hypervisor.c | 15 +++++++-------- > arch/x86/kernel/cpu/mshyperv.c | 13 ++++++++----- > arch/x86/kernel/cpu/vmware.c | 8 ++++---- > arch/x86/kernel/kvm.c | 6 ++---- > arch/x86/xen/enlighten.c | 9 +++------ > 6 files changed, 25 insertions(+), 28 deletions(-) > > 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 <asm/processor.h> > #include <asm/hypervisor.h> > > -/* > - * 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) > -- > 1.7.1 > > > -- To unsubscribe from this list: send the line "unsubscribe kvm" in the body of a message to majordomo@xxxxxxxxxxxxxxx More majordomo info at http://vger.kernel.org/majordomo-info.html
