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x86/vmware: Update platform detection code for VMCALL/VMMCALL hypercalls
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Vmware has historically used an INL instruction for this, but recent
hardware versions support using VMCALL/VMMCALL instead, so use this
method if supported at platform detection time. Explicitly code separate
macro versions since the alternatives self-patching has not been
performed at platform detection time.

Also put tighter constraints on the assembly input parameters.

Co-developed-by: Doug Covelli <dcovelli@vmware.com>
Signed-off-by: Doug Covelli <dcovelli@vmware.com>
Signed-off-by: Thomas Hellstrom <thellstrom@vmware.com>
Signed-off-by: Borislav Petkov <bp@suse.de>
Reviewed-by: Doug Covelli <dcovelli@vmware.com>
Cc: "H. Peter Anvin" <hpa@zytor.com>
Cc: Ingo Molnar <mingo@redhat.com>
Cc: linux-graphics-maintainer@vmware.com
Cc: Thomas Gleixner <tglx@linutronix.de>
Cc: virtualization@lists.linux-foundation.org
Cc: <pv-drivers@vmware.com>
Cc: x86-ml <x86@kernel.org>
Link: https://lkml.kernel.org/r/20190828080353.12658-2-thomas_os@shipmail.org
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Thomas Hellstrom authored and Borislav Petkov committed Aug 28, 2019
1 parent a55aa89 commit bac7b4e
Showing 1 changed file with 71 additions and 17 deletions.
88 changes: 71 additions & 17 deletions arch/x86/kernel/cpu/vmware.c
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Original file line number Diff line number Diff line change
Expand Up @@ -34,30 +34,65 @@
#undef pr_fmt
#define pr_fmt(fmt) "vmware: " fmt

#define CPUID_VMWARE_INFO_LEAF 0x40000000
#define CPUID_VMWARE_INFO_LEAF 0x40000000
#define CPUID_VMWARE_FEATURES_LEAF 0x40000010
#define CPUID_VMWARE_FEATURES_ECX_VMMCALL BIT(0)
#define CPUID_VMWARE_FEATURES_ECX_VMCALL BIT(1)

#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_CMD_GETVERSION 10
#define VMWARE_CMD_GETHZ 45
#define VMWARE_CMD_GETVCPU_INFO 68
#define VMWARE_CMD_LEGACY_X2APIC 3
#define VMWARE_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");
"=a"(eax), "=c"(ecx), "=d"(edx), "=b"(ebx) : \
"a"(VMWARE_HYPERVISOR_MAGIC), \
"c"(VMWARE_CMD_##cmd), \
"d"(VMWARE_HYPERVISOR_PORT), "b"(UINT_MAX) : \
"memory")

#define VMWARE_VMCALL(cmd, eax, ebx, ecx, edx) \
__asm__("vmcall" : \
"=a"(eax), "=c"(ecx), "=d"(edx), "=b"(ebx) : \
"a"(VMWARE_HYPERVISOR_MAGIC), \
"c"(VMWARE_CMD_##cmd), \
"d"(0), "b"(UINT_MAX) : \
"memory")

#define VMWARE_VMMCALL(cmd, eax, ebx, ecx, edx) \
__asm__("vmmcall" : \
"=a"(eax), "=c"(ecx), "=d"(edx), "=b"(ebx) : \
"a"(VMWARE_HYPERVISOR_MAGIC), \
"c"(VMWARE_CMD_##cmd), \
"d"(0), "b"(UINT_MAX) : \
"memory")

#define VMWARE_CMD(cmd, eax, ebx, ecx, edx) do { \
switch (vmware_hypercall_mode) { \
case CPUID_VMWARE_FEATURES_ECX_VMCALL: \
VMWARE_VMCALL(cmd, eax, ebx, ecx, edx); \
break; \
case CPUID_VMWARE_FEATURES_ECX_VMMCALL: \
VMWARE_VMMCALL(cmd, eax, ebx, ecx, edx); \
break; \
default: \
VMWARE_PORT(cmd, eax, ebx, ecx, edx); \
break; \
} \
} while (0)

static unsigned long vmware_tsc_khz __ro_after_init;
static u8 vmware_hypercall_mode __ro_after_init;

static inline int __vmware_platform(void)
{
uint32_t eax, ebx, ecx, edx;
VMWARE_PORT(GETVERSION, eax, ebx, ecx, edx);
VMWARE_CMD(GETVERSION, eax, ebx, ecx, edx);
return eax != (uint32_t)-1 && ebx == VMWARE_HYPERVISOR_MAGIC;
}

Expand Down Expand Up @@ -136,7 +171,7 @@ static void __init vmware_platform_setup(void)
uint32_t eax, ebx, ecx, edx;
uint64_t lpj, tsc_khz;

VMWARE_PORT(GETHZ, eax, ebx, ecx, edx);
VMWARE_CMD(GETHZ, eax, ebx, ecx, edx);

if (ebx != UINT_MAX) {
lpj = tsc_khz = eax | (((uint64_t)ebx) << 32);
Expand Down Expand Up @@ -174,10 +209,21 @@ static void __init vmware_platform_setup(void)
vmware_set_capabilities();
}

static u8 vmware_select_hypercall(void)
{
int eax, ebx, ecx, edx;

cpuid(CPUID_VMWARE_FEATURES_LEAF, &eax, &ebx, &ecx, &edx);
return (ecx & (CPUID_VMWARE_FEATURES_ECX_VMMCALL |
CPUID_VMWARE_FEATURES_ECX_VMCALL));
}

/*
* 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.
* If !boot_cpu_has(X86_FEATURE_HYPERVISOR), vmware_hypercall_mode
* intentionally defaults to 0.
*/
static uint32_t __init vmware_platform(void)
{
Expand All @@ -187,8 +233,16 @@ static uint32_t __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))
if (!memcmp(hyper_vendor_id, "VMwareVMware", 12)) {
if (eax >= CPUID_VMWARE_FEATURES_LEAF)
vmware_hypercall_mode =
vmware_select_hypercall();

pr_info("hypercall mode: 0x%02x\n",
(unsigned int) vmware_hypercall_mode);

return CPUID_VMWARE_INFO_LEAF;
}
} else if (dmi_available && dmi_name_in_serial("VMware") &&
__vmware_platform())
return 1;
Expand All @@ -200,9 +254,9 @@ static uint32_t __init vmware_platform(void)
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;
VMWARE_CMD(GETVCPU_INFO, eax, ebx, ecx, edx);
return (eax & (1 << VMWARE_CMD_VCPU_RESERVED)) == 0 &&
(eax & (1 << VMWARE_CMD_LEGACY_X2APIC)) != 0;
}

const __initconst struct hypervisor_x86 x86_hyper_vmware = {
Expand Down

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