From b4dd4f6e3648dfd66576515f2222d885a9a765c0 Mon Sep 17 00:00:00 2001 From: Thomas Hellstrom Date: Wed, 28 Aug 2019 10:03:51 +0200 Subject: [PATCH] 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 Signed-off-by: Borislav Petkov Reviewed-by: Doug Covelli Cc: Aaron Lewis Cc: "David S. Miller" Cc: Fenghua Yu Cc: Greg Kroah-Hartman Cc: "H. Peter Anvin" Cc: Ingo Molnar Cc: Josh Poimboeuf Cc: linux-graphics-maintainer@vmware.com Cc: Mauro Carvalho Chehab Cc: Nicolas Ferre Cc: Robert Hoo Cc: Thomas Gleixner Cc: virtualization@lists.linux-foundation.org Cc: Cc: x86-ml 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 diff --git a/MAINTAINERS b/MAINTAINERS index 9cbcf16..47efc1b 100644 --- a/MAINTAINERS +++ b/MAINTAINERS @@ -17206,6 +17206,7 @@ M: "VMware, Inc." 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 diff --git a/arch/x86/include/asm/cpufeatures.h b/arch/x86/include/asm/cpufeatures.h index e880f24..aaeae2f 100644 --- a/arch/x86/include/asm/cpufeatures.h +++ b/arch/x86/include/asm/cpufeatures.h @@ -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*/ diff --git a/arch/x86/include/asm/vmware.h b/arch/x86/include/asm/vmware.h new file mode 100644 index 0000000..e00c9e8 --- /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 +#include + +/* + * 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 diff --git a/arch/x86/kernel/cpu/vmware.c b/arch/x86/kernel/cpu/vmware.c index 757dded..9735139 100644 --- a/arch/x86/kernel/cpu/vmware.c +++ b/arch/x86/kernel/cpu/vmware.c @@ -30,6 +30,7 @@ #include #include #include +#include #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) -- 2.7.4