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: Thomas Hellstrom <thellstrom@vmware.com>
Signed-off-by: Borislav Petkov <bp@suse.de>
Reviewed-by: Doug 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

arch/x86/kernel/cpu/vmware.c

@@ -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)