From b4dd4f6e3648dfd66576515f2222d885a9a765c0 Mon Sep 17 00:00:00 2001
From: Thomas Hellstrom <thellstrom@vmware.com>
Date: Wed, 28 Aug 2019 10:03:51 +0200
Subject: [PATCH] x86/vmware: Add a header file for hypercall definitions
Git-commit: b4dd4f6e3648dfd66576515f2222d885a9a765c0
Patch-mainline: v5.4-rc1
References: bsc#1210327
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>
Acked-by: Ali Abdallah <ali.abdallah@suse.com>
Link: https://lkml.kernel.org/r/20190828080353.12658-3-thomas_os@shipmail.org
---
MAINTAINERS | 1
arch/x86/include/asm/cpufeatures.h | 2 +
arch/x86/include/asm/vmware.h | 53 +++++++++++++++++++++++++++++++++++++
arch/x86/kernel/cpu/vmware.c | 6 +++-
4 files changed, 61 insertions(+), 1 deletion(-)
create mode 100644 arch/x86/include/asm/vmware.h
--- a/MAINTAINERS
+++ b/MAINTAINERS
@@ -13973,6 +13973,7 @@ M: Alok Kataria <akataria@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 BALLOON DRIVER
M: Xavier Deguillard <xdeguillard@vmware.com>
--- /dev/null
+++ b/arch/x86/include/asm/vmware.h
@@ -0,0 +1,53 @@
+/* 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
--- a/arch/x86/kernel/cpu/vmware.c
+++ b/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_capabiliti
{
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)
--- a/arch/x86/include/asm/cpufeatures.h
+++ b/arch/x86/include/asm/cpufeatures.h
@@ -233,6 +233,8 @@
#define X86_FEATURE_VMMCALL ( 8*32+15) /* Prefer vmmcall to vmcall */
#define X86_FEATURE_XENPV ( 8*32+16) /* "" Xen paravirtual guest */
+#define X86_FEATURE_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) /* {RD/WR}{FS/GS}BASE instructions*/