[PATCH] x86/vmware: Add TDX hypercall support
From: Alexey Makhalov <alexey.makhalov@broadcom.com>
Date: 2023-12-08 02:32:49
Also in:
dri-devel, lkml, netdev, virtualization
Subsystem:
the rest, vmware hypervisor interface, x86 architecture (32-bit and 64-bit) · Maintainers:
Linus Torvalds, Ajay Kaher, Alexey Makhalov, Thomas Gleixner, Ingo Molnar, Borislav Petkov, Dave Hansen
From: Alexey Makhalov <redacted> VMware hypercalls use I/O port, VMCALL or VMMCALL instructions. Add __tdx_hypercall path to support TDX guests. No change in high bandwidth hypercalls, as only low bandwidth ones are supported for TDX guests. Co-developed-by: Tim Merrifield <redacted> Signed-off-by: Tim Merrifield <redacted> Signed-off-by: Alexey Makhalov <redacted> Reviewed-by: Nadav Amit <redacted> --- arch/x86/include/asm/vmware.h | 83 +++++++++++++++++++++++++++++++++++ arch/x86/kernel/cpu/vmware.c | 22 ++++++++++ 2 files changed, 105 insertions(+)
diff --git a/arch/x86/include/asm/vmware.h b/arch/x86/include/asm/vmware.h
index 719e41260ece..04c698b905ab 100644
--- a/arch/x86/include/asm/vmware.h
+++ b/arch/x86/include/asm/vmware.h@@ -34,12 +34,65 @@ #define VMWARE_CMD_GETHZ 45 #define VMWARE_CMD_GETVCPU_INFO 68 #define VMWARE_CMD_STEALCLOCK 91 +/* + * Hypercall command mask: + * bits[6:0] command, range [0, 127] + * bits[19:16] sub-command, range [0, 15] + */ +#define VMWARE_CMD_MASK 0xf007fULL #define CPUID_VMWARE_FEATURES_ECX_VMMCALL BIT(0) #define CPUID_VMWARE_FEATURES_ECX_VMCALL BIT(1) extern u8 vmware_hypercall_mode; +#define VMWARE_TDX_VENDOR_LEAF 0x1af7e4909ULL +#define VMWARE_TDX_HCALL_FUNC 1 + +extern unsigned long vmware_tdx_hypercall(struct tdx_module_args *args); + +/* + * TDCALL[TDG.VP.VMCALL] uses rax (arg0) and rcx (arg2), while the use of + * rbp (arg6) is discouraged by the TDX specification. Therefore, we + * remap those registers to r12, r13 and r14, respectively. + */ +static inline +unsigned long vmware_tdx_hypercall_args(unsigned long cmd, unsigned long in1, + unsigned long in3, unsigned long in4, + unsigned long in5, unsigned long in6, + uint32_t *out1, uint32_t *out2, + uint32_t *out3, uint32_t *out4, + uint32_t *out5, uint32_t *out6) +{ + unsigned long ret; + + struct tdx_module_args args = { + .r13 = cmd, + .rbx = in1, + .rdx = in3, + .rsi = in4, + .rdi = in5, + .r14 = in6, + }; + + ret = vmware_tdx_hypercall(&args); + + if (out1) + *out1 = args.rbx; + if (out2) + *out2 = args.r13; + if (out3) + *out3 = args.rdx; + if (out4) + *out4 = args.rsi; + if (out5) + *out5 = args.rdi; + if (out6) + *out6 = args.r14; + + return ret; +} + /* * The low bandwidth call. The low word of edx is presumed to have OUT bit * set. The high word of edx may contain input data from the caller.
@@ -67,6 +120,11 @@ unsigned long vmware_hypercall1(unsigned long cmd, unsigned long in1) { unsigned long out0; + if (cpu_feature_enabled(X86_FEATURE_TDX_GUEST)) + return vmware_tdx_hypercall_args(cmd, in1, 0, 0, 0, 0, + NULL, NULL, NULL, + NULL, NULL, NULL); + asm_inline volatile (VMWARE_HYPERCALL : "=a" (out0) : [port] "i" (VMWARE_HYPERVISOR_PORT),
@@ -85,6 +143,11 @@ unsigned long vmware_hypercall3(unsigned long cmd, unsigned long in1, { unsigned long out0; + if (cpu_feature_enabled(X86_FEATURE_TDX_GUEST)) + return vmware_tdx_hypercall_args(cmd, in1, 0, 0, 0, 0, + out1, out2, NULL, + NULL, NULL, NULL); + asm_inline volatile (VMWARE_HYPERCALL : "=a" (out0), "=b" (*out1), "=c" (*out2) : [port] "i" (VMWARE_HYPERVISOR_PORT),
@@ -104,6 +167,11 @@ unsigned long vmware_hypercall4(unsigned long cmd, unsigned long in1, { unsigned long out0; + if (cpu_feature_enabled(X86_FEATURE_TDX_GUEST)) + return vmware_tdx_hypercall_args(cmd, in1, 0, 0, 0, 0, + out1, out2, out3, + NULL, NULL, NULL); + asm_inline volatile (VMWARE_HYPERCALL : "=a" (out0), "=b" (*out1), "=c" (*out2), "=d" (*out3) : [port] "i" (VMWARE_HYPERVISOR_PORT),
@@ -123,6 +191,11 @@ unsigned long vmware_hypercall5(unsigned long cmd, unsigned long in1, { unsigned long out0; + if (cpu_feature_enabled(X86_FEATURE_TDX_GUEST)) + return vmware_tdx_hypercall_args(cmd, in1, in3, in4, in5, 0, + NULL, out2, NULL, + NULL, NULL, NULL); + asm_inline volatile (VMWARE_HYPERCALL : "=a" (out0), "=c" (*out2) : [port] "i" (VMWARE_HYPERVISOR_PORT),
@@ -145,6 +218,11 @@ unsigned long vmware_hypercall6(unsigned long cmd, unsigned long in1, { unsigned long out0; + if (cpu_feature_enabled(X86_FEATURE_TDX_GUEST)) + return vmware_tdx_hypercall_args(cmd, in1, in3, 0, 0, 0, + NULL, out2, out3, + out4, out5, NULL); + asm_inline volatile (VMWARE_HYPERCALL : "=a" (out0), "=c" (*out2), "=d" (*out3), "=S" (*out4), "=D" (*out5)
@@ -166,6 +244,11 @@ unsigned long vmware_hypercall7(unsigned long cmd, unsigned long in1, { unsigned long out0; + if (cpu_feature_enabled(X86_FEATURE_TDX_GUEST)) + return vmware_tdx_hypercall_args(cmd, in1, in3, in4, in5, 0, + out1, out2, out3, + NULL, NULL, NULL); + asm_inline volatile (VMWARE_HYPERCALL : "=a" (out0), "=b" (*out1), "=c" (*out2), "=d" (*out3) : [port] "i" (VMWARE_HYPERVISOR_PORT),
diff --git a/arch/x86/kernel/cpu/vmware.c b/arch/x86/kernel/cpu/vmware.c
index 3aa1adaed18f..bcf1d0fb3e89 100644
--- a/arch/x86/kernel/cpu/vmware.c
+++ b/arch/x86/kernel/cpu/vmware.c@@ -428,6 +428,28 @@ static bool __init vmware_legacy_x2apic_available(void) (eax & BIT(VCPU_LEGACY_X2APIC)); } +#ifdef CONFIG_INTEL_TDX_GUEST +unsigned long vmware_tdx_hypercall(struct tdx_module_args *args) +{ + if (!hypervisor_is_type(X86_HYPER_VMWARE)) + return 0; + + if (args->r13 & ~VMWARE_CMD_MASK) { + pr_warn("Out of range command %llx\n", args->r13); + return 0; + } + + args->r10 = VMWARE_TDX_VENDOR_LEAF; + args->r11 = VMWARE_TDX_HCALL_FUNC; + args->r12 = VMWARE_HYPERVISOR_MAGIC; + + __tdx_hypercall(args); + + return args->r12; +} +EXPORT_SYMBOL_GPL(vmware_tdx_hypercall); +#endif + #ifdef CONFIG_AMD_MEM_ENCRYPT static void vmware_sev_es_hcall_prepare(struct ghcb *ghcb, struct pt_regs *regs)
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2.39.0