Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1752581AbdFLOXG (ORCPT ); Mon, 12 Jun 2017 10:23:06 -0400 Received: from mx2.suse.de ([195.135.220.15]:45077 "EHLO mx1.suse.de" rhost-flags-OK-OK-OK-FAIL) by vger.kernel.org with ESMTP id S1752047AbdFLOWE (ORCPT ); Mon, 12 Jun 2017 10:22:04 -0400 From: Juergen Gross To: linux-kernel@vger.kernel.org, xen-devel@lists.xenproject.org Cc: boris.ostrovsky@oracle.com, gregkh@linuxfoundation.org, Juergen Gross Subject: [PATCH v3 2/4] xen: add sysfs node for guest type Date: Mon, 12 Jun 2017 16:21:48 +0200 Message-Id: <20170612142150.15283-3-jgross@suse.com> X-Mailer: git-send-email 2.12.3 In-Reply-To: <20170612142150.15283-1-jgross@suse.com> References: <20170612142150.15283-1-jgross@suse.com> Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org Content-Length: 6959 Lines: 195 Currently there is no reliable user interface inside a Xen guest to determine its type (e.g. HVM, PV or PVH). Instead of letting user mode try to determine this by various rather hacky mechanisms (parsing of boot messages before they are gone, trying to make use of known subtle differences in behavior of some instructions), add a sysfs node /sys/hypervisor/guest_type to explicitly deliver this information as it is known to the kernel. Signed-off-by: Juergen Gross Reviewed-by: Boris Ostrovsky --- V2: - remove PVHVM guest type (Andrew Cooper) - move description to Documentation/ABI/testing/sysfs-hypervisor-xen (Boris Ostrovsky) - make xen_guest_type const char * (Jan Beulich) - modify standard ARM guest type to "Xen" --- .../{sysfs-hypervisor-pmu => sysfs-hypervisor-xen} | 15 +++++++++++++-- MAINTAINERS | 2 +- arch/arm/xen/enlighten.c | 3 +++ arch/x86/xen/enlighten.c | 3 +++ arch/x86/xen/enlighten_hvm.c | 5 +++-- arch/x86/xen/enlighten_pv.c | 1 + drivers/xen/sys-hypervisor.c | 17 +++++++++++++++++ include/xen/xen.h | 2 ++ 8 files changed, 43 insertions(+), 5 deletions(-) rename Documentation/ABI/testing/{sysfs-hypervisor-pmu => sysfs-hypervisor-xen} (67%) diff --git a/Documentation/ABI/testing/sysfs-hypervisor-pmu b/Documentation/ABI/testing/sysfs-hypervisor-xen similarity index 67% rename from Documentation/ABI/testing/sysfs-hypervisor-pmu rename to Documentation/ABI/testing/sysfs-hypervisor-xen index 224faa105e18..c0edb3fdd6eb 100644 --- a/Documentation/ABI/testing/sysfs-hypervisor-pmu +++ b/Documentation/ABI/testing/sysfs-hypervisor-xen @@ -1,8 +1,19 @@ +What: /sys/hypervisor/guest_type +Date: May 2017 +KernelVersion: 4.13 +Contact: xen-devel@lists.xenproject.org +Description: If running under Xen: + Type of guest: + "Xen": standard guest type on arm + "HVM": fully virtualized guest (x86) + "PV": paravirtualized guest (x86) + "PVH": fully virtualized guest without legacy emulation (x86) + What: /sys/hypervisor/pmu/pmu_mode Date: August 2015 KernelVersion: 4.3 Contact: Boris Ostrovsky -Description: +Description: If running under Xen: Describes mode that Xen's performance-monitoring unit (PMU) uses. Accepted values are "off" -- PMU is disabled @@ -17,7 +28,7 @@ What: /sys/hypervisor/pmu/pmu_features Date: August 2015 KernelVersion: 4.3 Contact: Boris Ostrovsky -Description: +Description: If running under Xen: Describes Xen PMU features (as an integer). A set bit indicates that the corresponding feature is enabled. See include/xen/interface/xenpmu.h for available features diff --git a/MAINTAINERS b/MAINTAINERS index 68c31aebb79c..5630439429e6 100644 --- a/MAINTAINERS +++ b/MAINTAINERS @@ -13983,7 +13983,7 @@ F: arch/x86/include/asm/xen/ F: include/xen/ F: include/uapi/xen/ F: Documentation/ABI/stable/sysfs-hypervisor-xen -F: Documentation/ABI/testing/sysfs-hypervisor-pmu +F: Documentation/ABI/testing/sysfs-hypervisor-xen XEN HYPERVISOR ARM M: Stefano Stabellini diff --git a/arch/arm/xen/enlighten.c b/arch/arm/xen/enlighten.c index ba7f4c8f5c3e..7429af623379 100644 --- a/arch/arm/xen/enlighten.c +++ b/arch/arm/xen/enlighten.c @@ -43,6 +43,9 @@ EXPORT_SYMBOL(xen_start_info); enum xen_domain_type xen_domain_type = XEN_NATIVE; EXPORT_SYMBOL(xen_domain_type); +const char *xen_guest_type = "Xen"; +EXPORT_SYMBOL_GPL(xen_guest_type); + struct shared_info xen_dummy_shared_info; struct shared_info *HYPERVISOR_shared_info = (void *)&xen_dummy_shared_info; diff --git a/arch/x86/xen/enlighten.c b/arch/x86/xen/enlighten.c index a5ffcbb20cc0..17b6503df291 100644 --- a/arch/x86/xen/enlighten.c +++ b/arch/x86/xen/enlighten.c @@ -47,6 +47,9 @@ EXPORT_PER_CPU_SYMBOL(xen_vcpu_id); enum xen_domain_type xen_domain_type = XEN_NATIVE; EXPORT_SYMBOL_GPL(xen_domain_type); +const char *xen_guest_type = "HVM"; +EXPORT_SYMBOL_GPL(xen_guest_type); + unsigned long *machine_to_phys_mapping = (void *)MACH2PHYS_VIRT_START; EXPORT_SYMBOL(machine_to_phys_mapping); unsigned long machine_to_phys_nr; diff --git a/arch/x86/xen/enlighten_hvm.c b/arch/x86/xen/enlighten_hvm.c index a6d014f47e52..bda98726d139 100644 --- a/arch/x86/xen/enlighten_hvm.c +++ b/arch/x86/xen/enlighten_hvm.c @@ -68,9 +68,10 @@ static void __init init_hvm_pv_info(void) xen_domain_type = XEN_HVM_DOMAIN; /* PVH set up hypercall page in xen_prepare_pvh(). */ - if (xen_pvh_domain()) + if (xen_pvh_domain()) { pv_info.name = "Xen PVH"; - else { + xen_guest_type = "PVH"; + } else { u64 pfn; uint32_t msr; diff --git a/arch/x86/xen/enlighten_pv.c b/arch/x86/xen/enlighten_pv.c index f33eef4ebd12..7ac5e93d96f3 100644 --- a/arch/x86/xen/enlighten_pv.c +++ b/arch/x86/xen/enlighten_pv.c @@ -1255,6 +1255,7 @@ asmlinkage __visible void __init xen_start_kernel(void) return; xen_domain_type = XEN_PV_DOMAIN; + xen_guest_type = "PV"; xen_setup_features(); diff --git a/drivers/xen/sys-hypervisor.c b/drivers/xen/sys-hypervisor.c index 84106f9c456c..d641e9970d5d 100644 --- a/drivers/xen/sys-hypervisor.c +++ b/drivers/xen/sys-hypervisor.c @@ -50,6 +50,18 @@ static int __init xen_sysfs_type_init(void) return sysfs_create_file(hypervisor_kobj, &type_attr.attr); } +static ssize_t guest_type_show(struct hyp_sysfs_attr *attr, char *buffer) +{ + return sprintf(buffer, "%s\n", xen_guest_type); +} + +HYPERVISOR_ATTR_RO(guest_type); + +static int __init xen_sysfs_guest_type_init(void) +{ + return sysfs_create_file(hypervisor_kobj, &guest_type_attr.attr); +} + /* xen version attributes */ static ssize_t major_show(struct hyp_sysfs_attr *attr, char *buffer) { @@ -471,6 +483,9 @@ static int __init hyper_sysfs_init(void) ret = xen_sysfs_type_init(); if (ret) goto out; + ret = xen_sysfs_guest_type_init(); + if (ret) + goto guest_type_out; ret = xen_sysfs_version_init(); if (ret) goto version_out; @@ -502,6 +517,8 @@ static int __init hyper_sysfs_init(void) comp_out: sysfs_remove_group(hypervisor_kobj, &version_group); version_out: + sysfs_remove_file(hypervisor_kobj, &guest_type_attr.attr); +guest_type_out: sysfs_remove_file(hypervisor_kobj, &type_attr.attr); out: return ret; diff --git a/include/xen/xen.h b/include/xen/xen.h index 6e8b7fc79801..f02d1732d7a6 100644 --- a/include/xen/xen.h +++ b/include/xen/xen.h @@ -9,8 +9,10 @@ enum xen_domain_type { #ifdef CONFIG_XEN extern enum xen_domain_type xen_domain_type; +extern const char *xen_guest_type; #else #define xen_domain_type XEN_NATIVE +#define xen_guest_type "native" #endif #define xen_domain() (xen_domain_type != XEN_NATIVE) -- 2.12.3