From bac7b4e843232a3a49a042410cf743341eb0887e Mon Sep 17 00:00:00 2001 From: Thomas Hellstrom Date: Wed, 28 Aug 2019 10:03:50 +0200 Subject: 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: Doug Covelli Signed-off-by: Doug Covelli Signed-off-by: Thomas Hellstrom Signed-off-by: Borislav Petkov Reviewed-by: Doug Covelli Cc: "H. Peter Anvin" Cc: Ingo Molnar Cc: linux-graphics-maintainer@vmware.com Cc: Thomas Gleixner Cc: virtualization@lists.linux-foundation.org Cc: Cc: x86-ml Link: https://lkml.kernel.org/r/20190828080353.12658-2-thomas_os@shipmail.org --- arch/x86/kernel/cpu/vmware.c | 88 +++++++++++++++++++++++++++++++++++--------- 1 file changed, 71 insertions(+), 17 deletions(-) (limited to 'arch') diff --git a/arch/x86/kernel/cpu/vmware.c b/arch/x86/kernel/cpu/vmware.c index 3c648476d4fb..757dded223af 100644 --- a/arch/x86/kernel/cpu/vmware.c +++ b/arch/x86/kernel/cpu/vmware.c @@ -34,30 +34,65 @@ #undef pr_fmt #define pr_fmt(fmt) "vmware: " fmt -#define CPUID_VMWARE_INFO_LEAF 0x40000000 +#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"(eax), "=c"(ecx), "=d"(edx), "=b"(ebx) : \ + "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 = { -- cgit From b4dd4f6e3648dfd66576515f2222d885a9a765c0 Mon Sep 17 00:00:00 2001 From: Thomas Hellstrom Date: Wed, 28 Aug 2019 10:03:51 +0200 Subject: 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 --- arch/x86/include/asm/cpufeatures.h | 2 ++ arch/x86/include/asm/vmware.h | 53 ++++++++++++++++++++++++++++++++++++++ arch/x86/kernel/cpu/vmware.c | 6 ++++- 3 files changed, 60 insertions(+), 1 deletion(-) create mode 100644 arch/x86/include/asm/vmware.h (limited to 'arch') diff --git a/arch/x86/include/asm/cpufeatures.h b/arch/x86/include/asm/cpufeatures.h index e880f2408e29..aaeae2fa49a5 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 000000000000..e00c9e875933 --- /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 757dded223af..9735139cfdf8 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) -- cgit