From: Thiago Jung Bauermann <bauerman@linux.ibm.com>
To: linuxppc-dev@lists.ozlabs.org
Cc: linux-kernel@vger.kernel.org,
Alexey Kardashevskiy <aik@ozlabs.ru>,
Anshuman Khandual <anshuman.linux@gmail.com>,
Benjamin Herrenschmidt <benh@kernel.crashing.org>,
Christoph Hellwig <hch@lst.de>,
Michael Ellerman <mpe@ellerman.id.au>,
Mike Anderson <andmike@linux.ibm.com>,
Paul Mackerras <paulus@samba.org>, Ram Pai <linuxram@us.ibm.com>,
Claudio Carvalho <cclaudio@linux.ibm.com>,
Ryan Grimm <grimm@linux.vnet.ibm.com>,
Thiago Jung Bauermann <bauerman@linux.ibm.com>
Subject: [RFC PATCH v4 11/16] powerpc/pseries/svm: Export guest SVM status to user space via sysfs
Date: Mon, 19 Aug 2019 23:13:21 -0300 [thread overview]
Message-ID: <20190820021326.6884-12-bauerman@linux.ibm.com> (raw)
In-Reply-To: <20190820021326.6884-1-bauerman@linux.ibm.com>
From: Ryan Grimm <grimm@linux.vnet.ibm.com>
User space might want to know it's running in a secure VM. It can't do
a mfmsr because mfmsr is a privileged instruction.
The solution here is to create a cpu attribute:
/sys/devices/system/cpu/svm
which will read 0 or 1 based on the S bit of the current CPU.
Signed-off-by: Ryan Grimm <grimm@linux.vnet.ibm.com>
Signed-off-by: Thiago Jung Bauermann <bauerman@linux.ibm.com>
---
.../ABI/testing/sysfs-devices-system-cpu | 10 ++++++++++
arch/powerpc/kernel/sysfs.c | 20 +++++++++++++++++++
2 files changed, 30 insertions(+)
diff --git a/Documentation/ABI/testing/sysfs-devices-system-cpu b/Documentation/ABI/testing/sysfs-devices-system-cpu
index 5f7d7b14fa44..06d0931119cc 100644
--- a/Documentation/ABI/testing/sysfs-devices-system-cpu
+++ b/Documentation/ABI/testing/sysfs-devices-system-cpu
@@ -562,3 +562,13 @@ Description: Umwait control
or C0.2 state. The time is an unsigned 32-bit number.
Note that a value of zero means there is no limit.
Low order two bits must be zero.
+
+What: /sys/devices/system/cpu/svm
+Date: August 2019
+Contact: Linux kernel mailing list <linux-kernel@vger.kernel.org>
+ Linux for PowerPC mailing list <linuxppc-dev@ozlabs.org>
+Description: Secure Virtual Machine
+
+ If 1, it means the system is using the Protected Execution
+ Facility in POWER9 and newer processors. i.e., it is a Secure
+ Virtual Machine.
diff --git a/arch/powerpc/kernel/sysfs.c b/arch/powerpc/kernel/sysfs.c
index e2147d7c9e72..80a676da11cb 100644
--- a/arch/powerpc/kernel/sysfs.c
+++ b/arch/powerpc/kernel/sysfs.c
@@ -19,6 +19,7 @@
#include <asm/smp.h>
#include <asm/pmc.h>
#include <asm/firmware.h>
+#include <asm/svm.h>
#include "cacheinfo.h"
#include "setup.h"
@@ -715,6 +716,23 @@ static struct device_attribute pa6t_attrs[] = {
#endif /* HAS_PPC_PMC_PA6T */
#endif /* HAS_PPC_PMC_CLASSIC */
+#ifdef CONFIG_PPC_SVM
+static ssize_t show_svm(struct device *dev, struct device_attribute *attr, char *buf)
+{
+ return sprintf(buf, "%u\n", is_secure_guest());
+}
+static DEVICE_ATTR(svm, 0444, show_svm, NULL);
+
+static void create_svm_file(void)
+{
+ device_create_file(cpu_subsys.dev_root, &dev_attr_svm);
+}
+#else
+static void create_svm_file(void)
+{
+}
+#endif /* CONFIG_PPC_SVM */
+
static int register_cpu_online(unsigned int cpu)
{
struct cpu *c = &per_cpu(cpu_devices, cpu);
@@ -1058,6 +1076,8 @@ static int __init topology_init(void)
sysfs_create_dscr_default();
#endif /* CONFIG_PPC64 */
+ create_svm_file();
+
return 0;
}
subsys_initcall(topology_init);
next prev parent reply other threads:[~2019-08-20 2:16 UTC|newest]
Thread overview: 21+ messages / expand[flat|nested] mbox.gz Atom feed top
2019-08-20 2:13 [PATCH v4 00/16] Secure Virtual Machine Enablement Thiago Jung Bauermann
2019-08-20 2:13 ` [PATCH v4 01/16] powerpc/kernel: Add ucall_norets() ultravisor call handler Thiago Jung Bauermann
2019-08-20 2:13 ` [PATCH v4 02/16] powerpc/pseries: Introduce option to build secure virtual machines Thiago Jung Bauermann
2019-09-02 3:29 ` Michael Ellerman
2019-09-03 18:53 ` Thiago Jung Bauermann
2019-09-05 4:03 ` Michael Ellerman
2019-09-05 16:06 ` Thiago Jung Bauermann
2019-08-20 2:13 ` [PATCH v4 03/16] powerpc: Add support for adding an ESM blob to the zImage wrapper Thiago Jung Bauermann
2019-08-20 2:13 ` [PATCH v4 04/16] powerpc/prom_init: Add the ESM call to prom_init Thiago Jung Bauermann
2019-08-20 2:13 ` [PATCH v4 05/16] powerpc/pseries/svm: Add helpers for UV_SHARE_PAGE and UV_UNSHARE_PAGE Thiago Jung Bauermann
2019-08-20 2:13 ` [PATCH v4 06/16] powerpc: Introduce the MSR_S bit Thiago Jung Bauermann
2019-08-20 2:13 ` [PATCH v4 07/16] powerpc/pseries: Add and use LPPACA_SIZE constant Thiago Jung Bauermann
2019-08-20 2:13 ` [PATCH v4 08/16] powerpc/pseries/svm: Use shared memory for LPPACA structures Thiago Jung Bauermann
2019-08-20 2:13 ` [PATCH v4 09/16] powerpc/pseries/svm: Use shared memory for Debug Trace Log (DTL) Thiago Jung Bauermann
2019-08-20 2:13 ` [PATCH v4 10/16] powerpc/pseries/svm: Unshare all pages before kexecing a new kernel Thiago Jung Bauermann
2019-08-20 2:13 ` Thiago Jung Bauermann [this message]
2019-08-20 2:13 ` [PATCH v4 12/16] powerpc/pseries/svm: Disable doorbells in SVM guests Thiago Jung Bauermann
2019-08-20 2:13 ` [PATCH v4 13/16] powerpc/pseries/iommu: Don't use dma_iommu_ops on secure guests Thiago Jung Bauermann
2019-08-20 2:13 ` [PATCH v4 14/16] powerpc/pseries/svm: Force SWIOTLB for " Thiago Jung Bauermann
2019-08-20 2:13 ` [PATCH v4 15/16] Documentation/powerpc: Ultravisor API Thiago Jung Bauermann
2019-08-20 2:13 ` [PATCH v4 16/16] powerpc/configs: Enable secure guest support in pseries and ppc64 defconfigs Thiago Jung Bauermann
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