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authorAndré Fabian Silva Delgado <emulatorman@parabola.nu>2015-08-05 17:04:01 -0300
committerAndré Fabian Silva Delgado <emulatorman@parabola.nu>2015-08-05 17:04:01 -0300
commit57f0f512b273f60d52568b8c6b77e17f5636edc0 (patch)
tree5e910f0e82173f4ef4f51111366a3f1299037a7b /arch/x86/kernel/cpu/vmware.c
Initial import
Diffstat (limited to 'arch/x86/kernel/cpu/vmware.c')
-rw-r--r--arch/x86/kernel/cpu/vmware.c147
1 files changed, 147 insertions, 0 deletions
diff --git a/arch/x86/kernel/cpu/vmware.c b/arch/x86/kernel/cpu/vmware.c
new file mode 100644
index 000000000..628a059a9
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+++ b/arch/x86/kernel/cpu/vmware.c
@@ -0,0 +1,147 @@
+/*
+ * VMware Detection code.
+ *
+ * Copyright (C) 2008, VMware, Inc.
+ * Author : Alok N Kataria <akataria@vmware.com>
+ *
+ * This program is free software; you can redistribute it and/or modify
+ * it under the terms of the GNU General Public License as published by
+ * the Free Software Foundation; either version 2 of the License, or
+ * (at your option) any later version.
+ *
+ * This program is distributed in the hope that it will be useful, but
+ * WITHOUT ANY WARRANTY; without even the implied warranty of
+ * MERCHANTABILITY OR FITNESS FOR A PARTICULAR PURPOSE, GOOD TITLE or
+ * NON INFRINGEMENT. See the GNU General Public License for more
+ * details.
+ *
+ * You should have received a copy of the GNU General Public License
+ * along with this program; if not, write to the Free Software
+ * Foundation, Inc., 51 Franklin St, Fifth Floor, Boston, MA 02110-1301 USA.
+ *
+ */
+
+#include <linux/dmi.h>
+#include <linux/module.h>
+#include <asm/div64.h>
+#include <asm/x86_init.h>
+#include <asm/hypervisor.h>
+
+#define CPUID_VMWARE_INFO_LEAF 0x40000000
+#define VMWARE_HYPERVISOR_MAGIC 0x564D5868
+#define VMWARE_HYPERVISOR_PORT 0x5658
+
+#define VMWARE_PORT_CMD_GETVERSION 10
+#define VMWARE_PORT_CMD_GETHZ 45
+#define VMWARE_PORT_CMD_GETVCPU_INFO 68
+#define VMWARE_PORT_CMD_LEGACY_X2APIC 3
+#define VMWARE_PORT_CMD_VCPU_RESERVED 31
+
+#define VMWARE_PORT(cmd, eax, ebx, ecx, edx) \
+ __asm__("inl (%%dx)" : \
+ "=a"(eax), "=c"(ecx), "=d"(edx), "=b"(ebx) : \
+ "0"(VMWARE_HYPERVISOR_MAGIC), \
+ "1"(VMWARE_PORT_CMD_##cmd), \
+ "2"(VMWARE_HYPERVISOR_PORT), "3"(UINT_MAX) : \
+ "memory");
+
+static inline int __vmware_platform(void)
+{
+ uint32_t eax, ebx, ecx, edx;
+ VMWARE_PORT(GETVERSION, eax, ebx, ecx, edx);
+ return eax != (uint32_t)-1 && ebx == VMWARE_HYPERVISOR_MAGIC;
+}
+
+static unsigned long vmware_get_tsc_khz(void)
+{
+ uint64_t tsc_hz, lpj;
+ uint32_t eax, ebx, ecx, edx;
+
+ VMWARE_PORT(GETHZ, eax, ebx, ecx, edx);
+
+ tsc_hz = eax | (((uint64_t)ebx) << 32);
+ do_div(tsc_hz, 1000);
+ BUG_ON(tsc_hz >> 32);
+ printk(KERN_INFO "TSC freq read from hypervisor : %lu.%03lu MHz\n",
+ (unsigned long) tsc_hz / 1000,
+ (unsigned long) tsc_hz % 1000);
+
+ if (!preset_lpj) {
+ lpj = ((u64)tsc_hz * 1000);
+ do_div(lpj, HZ);
+ preset_lpj = lpj;
+ }
+
+ return tsc_hz;
+}
+
+static void __init vmware_platform_setup(void)
+{
+ uint32_t eax, ebx, ecx, edx;
+
+ VMWARE_PORT(GETHZ, eax, ebx, ecx, edx);
+
+ if (ebx != UINT_MAX)
+ x86_platform.calibrate_tsc = vmware_get_tsc_khz;
+ else
+ printk(KERN_WARNING
+ "Failed to get TSC freq from the hypervisor\n");
+}
+
+/*
+ * While checking the dmi string information, just checking the product
+ * serial key should be enough, as this will always have a VMware
+ * specific string when running under VMware hypervisor.
+ */
+static uint32_t __init vmware_platform(void)
+{
+ if (cpu_has_hypervisor) {
+ unsigned int eax;
+ unsigned int hyper_vendor_id[3];
+
+ 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 CPUID_VMWARE_INFO_LEAF;
+ } else if (dmi_available && dmi_name_in_serial("VMware") &&
+ __vmware_platform())
+ return 1;
+
+ return 0;
+}
+
+/*
+ * VMware hypervisor takes care of exporting a reliable TSC to the guest.
+ * Still, due to timing difference when running on virtual cpus, the TSC can
+ * be marked as unstable in some cases. For example, the TSC sync check at
+ * bootup can fail due to a marginal offset between vcpus' TSCs (though the
+ * TSCs do not drift from each other). Also, the ACPI PM timer clocksource
+ * is not suitable as a watchdog when running on a hypervisor because the
+ * kernel may miss a wrap of the counter if the vcpu is descheduled for a
+ * long time. To skip these checks at runtime we set these capability bits,
+ * so that the kernel could just trust the hypervisor with providing a
+ * reliable virtual TSC that is suitable for timekeeping.
+ */
+static void vmware_set_cpu_features(struct cpuinfo_x86 *c)
+{
+ set_cpu_cap(c, X86_FEATURE_CONSTANT_TSC);
+ set_cpu_cap(c, X86_FEATURE_TSC_RELIABLE);
+}
+
+/* Checks if hypervisor supports x2apic without VT-D interrupt remapping. */
+static bool __init vmware_legacy_x2apic_available(void)
+{
+ uint32_t eax, ebx, ecx, edx;
+ VMWARE_PORT(GETVCPU_INFO, eax, ebx, ecx, edx);
+ return (eax & (1 << VMWARE_PORT_CMD_VCPU_RESERVED)) == 0 &&
+ (eax & (1 << VMWARE_PORT_CMD_LEGACY_X2APIC)) != 0;
+}
+
+const __refconst struct hypervisor_x86 x86_hyper_vmware = {
+ .name = "VMware",
+ .detect = vmware_platform,
+ .set_cpu_features = vmware_set_cpu_features,
+ .init_platform = vmware_platform_setup,
+ .x2apic_available = vmware_legacy_x2apic_available,
+};
+EXPORT_SYMBOL(x86_hyper_vmware);