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Commit b4dd4f6e authored by Thomas Hellstrom's avatar Thomas Hellstrom Committed by Borislav Petkov
Browse files

x86/vmware: Add a header file for hypercall definitions 



The new header is intended to be used by drivers using the backdoor.
Follow the KVM example using alternatives self-patching to choose
between vmcall, vmmcall and io instructions.

Also define two new CPU feature flags to indicate hypervisor support
for vmcall- and vmmcall instructions. The new XF86_FEATURE_VMW_VMMCALL
flag is needed because using XF86_FEATURE_VMMCALL might break QEMU/KVM
setups using the vmmouse driver. They rely on XF86_FEATURE_VMMCALL
on AMD to get the kvm_hypercall() right. But they do not yet implement
vmmcall for the VMware hypercall used by the vmmouse driver.

 [ bp: reflow hypercall %edx usage explanation comment. ]

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: Aaron Lewis <aaronlewis@google.com>
Cc: "David S. Miller" <davem@davemloft.net>
Cc: Fenghua Yu <fenghua.yu@intel.com>
Cc: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
Cc: "H. Peter Anvin" <hpa@zytor.com>
Cc: Ingo Molnar <mingo@redhat.com>
Cc: Josh Poimboeuf <jpoimboe@redhat.com>
Cc: linux-graphics-maintainer@vmware.com
Cc: Mauro Carvalho Chehab <mchehab+samsung@kernel.org>
Cc: Nicolas Ferre <nicolas.ferre@microchip.com>
Cc: Robert Hoo <robert.hu@linux.intel.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/20190828080353.12658-3-thomas_os@shipmail.org
parent bac7b4e8

MAINTAINERS

+1 −0
Original line number Diff line number Diff line
@@ -17206,6 +17206,7 @@ M: "VMware, Inc." <pv-drivers@vmware.com> 
L:	virtualization@lists.linux-foundation.org

S:	Supported

F:	arch/x86/kernel/cpu/vmware.c

F:	arch/x86/include/asm/vmware.h



VMWARE PVRDMA DRIVER

M:	Adit Ranadive <aditr@vmware.com>

arch/x86/include/asm/cpufeatures.h

+2 −0
Original line number Diff line number Diff line
@@ -232,6 +232,8 @@ 
#define X86_FEATURE_VMMCALL		( 8*32+15) /* Prefer VMMCALL to VMCALL */

#define X86_FEATURE_XENPV		( 8*32+16) /* "" Xen paravirtual guest */

#define X86_FEATURE_EPT_AD		( 8*32+17) /* Intel Extended Page Table access-dirty bit */

#define X86_FEATURE_VMCALL		( 8*32+18) /* "" Hypervisor supports the VMCALL instruction */

#define X86_FEATURE_VMW_VMMCALL		( 8*32+19) /* "" VMware prefers VMMCALL hypercall instruction */



/* Intel-defined CPU features, CPUID level 0x00000007:0 (EBX), word 9 */

#define X86_FEATURE_FSGSBASE		( 9*32+ 0) /* RDFSBASE, WRFSBASE, RDGSBASE, WRGSBASE instructions*/

arch/x86/include/asm/vmware.h

0 → 100644
+53 −0
Original line number Diff line number Diff line 
/* SPDX-License-Identifier: GPL-2.0 or MIT */

#ifndef _ASM_X86_VMWARE_H

#define _ASM_X86_VMWARE_H



#include <asm/cpufeatures.h>

#include <asm/alternative.h>



/*

 * The hypercall definitions differ in the low word of the %edx argument

 * in the following way: the old port base interface uses the port

 * number to distinguish between high- and low bandwidth versions.

 *

 * The new vmcall interface instead uses a set of flags to select

 * bandwidth mode and transfer direction. The flags should be loaded

 * into %dx by any user and are automatically replaced by the port

 * number if the VMWARE_HYPERVISOR_PORT method is used.

 *

 * In short, new driver code should strictly use the new definition of

 * %dx content.

 */



/* Old port-based version */

#define VMWARE_HYPERVISOR_PORT    "0x5658"

#define VMWARE_HYPERVISOR_PORT_HB "0x5659"



/* Current vmcall / vmmcall version */

#define VMWARE_HYPERVISOR_HB   BIT(0)

#define VMWARE_HYPERVISOR_OUT  BIT(1)



/* The low bandwidth call. The low word of edx is presumed clear. */

#define VMWARE_HYPERCALL						\

	ALTERNATIVE_2("movw $" VMWARE_HYPERVISOR_PORT ", %%dx; inl (%%dx)", \

		      "vmcall", X86_FEATURE_VMCALL,			\

		      "vmmcall", X86_FEATURE_VMW_VMMCALL)



/*

 * The high bandwidth out call. The low word of edx is presumed to have the

 * HB and OUT bits set.

 */

#define VMWARE_HYPERCALL_HB_OUT						\

	ALTERNATIVE_2("movw $" VMWARE_HYPERVISOR_PORT_HB ", %%dx; rep outsb", \

		      "vmcall", X86_FEATURE_VMCALL,			\

		      "vmmcall", X86_FEATURE_VMW_VMMCALL)



/*

 * The high bandwidth in call. The low word of edx is presumed to have the

 * HB bit set.

 */

#define VMWARE_HYPERCALL_HB_IN						\

	ALTERNATIVE_2("movw $" VMWARE_HYPERVISOR_PORT_HB ", %%dx; rep insb", \

		      "vmcall", X86_FEATURE_VMCALL,			\

		      "vmmcall", X86_FEATURE_VMW_VMMCALL)

#endif

arch/x86/kernel/cpu/vmware.c

+5 −1
Original line number Diff line number Diff line
@@ -30,6 +30,7 @@ 
#include <asm/hypervisor.h>

#include <asm/timer.h>

#include <asm/apic.h>

#include <asm/vmware.h>



#undef pr_fmt

#define pr_fmt(fmt)	"vmware: " fmt
@@ -40,7 +41,6 @@ 
#define CPUID_VMWARE_FEATURES_ECX_VMCALL     BIT(1)



#define VMWARE_HYPERVISOR_MAGIC	0x564D5868

#define VMWARE_HYPERVISOR_PORT	0x5658



#define VMWARE_CMD_GETVERSION    10

#define VMWARE_CMD_GETHZ         45
@@ -164,6 +164,10 @@ static void __init vmware_set_capabilities(void) 
{

	setup_force_cpu_cap(X86_FEATURE_CONSTANT_TSC);

	setup_force_cpu_cap(X86_FEATURE_TSC_RELIABLE);

	if (vmware_hypercall_mode == CPUID_VMWARE_FEATURES_ECX_VMCALL)

		setup_force_cpu_cap(X86_FEATURE_VMCALL);

	else if (vmware_hypercall_mode == CPUID_VMWARE_FEATURES_ECX_VMMCALL)

		setup_force_cpu_cap(X86_FEATURE_VMW_VMMCALL);

}



static void __init vmware_platform_setup(void)