Commit bac7b4e8 authored by Thomas Hellstrom's avatar Thomas Hellstrom Committed by Borislav Petkov
Browse files

x86/vmware: Update platform detection code for VMCALL/VMMCALL hypercalls 



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: default avatarDoug Covelli <dcovelli@vmware.com>
Signed-off-by: default avatarDoug Covelli <dcovelli@vmware.com>
Signed-off-by: default avatarThomas Hellstrom <thellstrom@vmware.com>
Signed-off-by: default avatarBorislav Petkov <bp@suse.de>
Reviewed-by: default avatarDoug 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
parent a55aa89a

arch/x86/kernel/cpu/vmware.c

+71 −17
Original line number Diff line number Diff line
@@ -35,29 +35,64 @@ 
#define pr_fmt(fmt)	"vmware: " fmt



#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"(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;

}
@@ -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);
@@ -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)

{
@@ -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;
@@ -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 = {

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