Re: [PATCH v8 018/103] KVM: TDX: Stub in tdx.h with structs, accessors, and VMCS helpers
From: Binbin Wu
Date: Mon Aug 22 2022 - 23:40:04 EST
On 2022/8/8 6:01, isaku.yamahata@xxxxxxxxx wrote:
From: Sean Christopherson <sean.j.christopherson@xxxxxxxxx>
Stub in kvm_tdx, vcpu_tdx, and their various accessors. TDX defines
SEAMCALL APIs to access TDX control structures corresponding to the VMX
VMCS. Introduce helper accessors to hide its SEAMCALL ABI details.
Signed-off-by: Sean Christopherson <sean.j.christopherson@xxxxxxxxx>
Signed-off-by: Isaku Yamahata <isaku.yamahata@xxxxxxxxx>
---
arch/x86/kvm/vmx/tdx.h | 103 ++++++++++++++++++++++++++++++++++++++++-
1 file changed, 101 insertions(+), 2 deletions(-)
diff --git a/arch/x86/kvm/vmx/tdx.h b/arch/x86/kvm/vmx/tdx.h
index 2f43db5bbefb..f50d37f3fc9c 100644
--- a/arch/x86/kvm/vmx/tdx.h
+++ b/arch/x86/kvm/vmx/tdx.h
@@ -3,16 +3,29 @@
#define __KVM_X86_TDX_H
#ifdef CONFIG_INTEL_TDX_HOST
+
+#include "tdx_ops.h"
+
int tdx_module_setup(void);
+struct tdx_td_page {
+ unsigned long va;
+ hpa_t pa;
+ bool added;
+};
+
struct kvm_tdx {
struct kvm kvm;
- /* TDX specific members follow. */
+
+ struct tdx_td_page tdr;
+ struct tdx_td_page *tdcs;
};
struct vcpu_tdx {
struct kvm_vcpu vcpu;
- /* TDX specific members follow. */
+
+ struct tdx_td_page tdvpr;
+ struct tdx_td_page *tdvpx;
};
static inline bool is_td(struct kvm *kvm)
@@ -34,6 +47,92 @@ static inline struct vcpu_tdx *to_tdx(struct kvm_vcpu *vcpu)
{
return container_of(vcpu, struct vcpu_tdx, vcpu);
}
+
+static __always_inline void tdvps_vmcs_check(u32 field, u8 bits)
+{
+ BUILD_BUG_ON_MSG(__builtin_constant_p(field) && (field) & 0x1,
+ "Read/Write to TD VMCS *_HIGH fields not supported");
+
+ BUILD_BUG_ON(bits != 16 && bits != 32 && bits != 64);
+
+ BUILD_BUG_ON_MSG(bits != 64 && __builtin_constant_p(field) &&
+ (((field) & 0x6000) == 0x2000 ||
+ ((field) & 0x6000) == 0x6000),
+ "Invalid TD VMCS access for 64-bit field");
if bits is 64 here, "bits != 64" is false, how could this check for
"Invalid TD VMCS access for 64-bit field"?
+ BUILD_BUG_ON_MSG(bits != 32 && __builtin_constant_p(field) &&
+ ((field) & 0x6000) == 0x4000,
+ "Invalid TD VMCS access for 32-bit field");
ditto
+ BUILD_BUG_ON_MSG(bits != 16 && __builtin_constant_p(field) &&
+ ((field) & 0x6000) == 0x0000,
+ "Invalid TD VMCS access for 16-bit field");
ditto
+}
+
+static __always_inline void tdvps_state_non_arch_check(u64 field, u8 bits) {}
+static __always_inline void tdvps_management_check(u64 field, u8 bits) {}
+
+#define TDX_BUILD_TDVPS_ACCESSORS(bits, uclass, lclass) \
+static __always_inline u##bits td_##lclass##_read##bits(struct vcpu_tdx *tdx, \
+ u32 field) \
+{ \
+ struct tdx_module_output out; \
+ u64 err; \
+ \
+ tdvps_##lclass##_check(field, bits); \
+ err = tdh_vp_rd(tdx->tdvpr.pa, TDVPS_##uclass(field), &out); \
+ if (unlikely(err)) { \
+ pr_err("TDH_VP_RD["#uclass".0x%x] failed: 0x%llx\n", \
+ field, err); \
+ return 0; \
+ } \
+ return (u##bits)out.r8; \
+} \
+static __always_inline void td_##lclass##_write##bits(struct vcpu_tdx *tdx, \
+ u32 field, u##bits val) \
+{ \
+ struct tdx_module_output out; \
+ u64 err; \
+ \
+ tdvps_##lclass##_check(field, bits); \
+ err = tdh_vp_wr(tdx->tdvpr.pa, TDVPS_##uclass(field), val, \
+ GENMASK_ULL(bits - 1, 0), &out); \
+ if (unlikely(err)) \
+ pr_err("TDH_VP_WR["#uclass".0x%x] = 0x%llx failed: 0x%llx\n", \
+ field, (u64)val, err); \
+} \
+static __always_inline void td_##lclass##_setbit##bits(struct vcpu_tdx *tdx, \
+ u32 field, u64 bit) \
+{ \
+ struct tdx_module_output out; \
+ u64 err; \
+ \
+ tdvps_##lclass##_check(field, bits); \
+ err = tdh_vp_wr(tdx->tdvpr.pa, TDVPS_##uclass(field), bit, bit, \
+ &out); \
+ if (unlikely(err)) \
+ pr_err("TDH_VP_WR["#uclass".0x%x] |= 0x%llx failed: 0x%llx\n", \
+ field, bit, err); \
+} \
+static __always_inline void td_##lclass##_clearbit##bits(struct vcpu_tdx *tdx, \
+ u32 field, u64 bit) \
+{ \
+ struct tdx_module_output out; \
+ u64 err; \
+ \
+ tdvps_##lclass##_check(field, bits); \
+ err = tdh_vp_wr(tdx->tdvpr.pa, TDVPS_##uclass(field), 0, bit, \
+ &out); \
+ if (unlikely(err)) \
+ pr_err("TDH_VP_WR["#uclass".0x%x] &= ~0x%llx failed: 0x%llx\n", \
+ field, bit, err); \
+}
+
+TDX_BUILD_TDVPS_ACCESSORS(16, VMCS, vmcs);
+TDX_BUILD_TDVPS_ACCESSORS(32, VMCS, vmcs);
+TDX_BUILD_TDVPS_ACCESSORS(64, VMCS, vmcs);
+
+TDX_BUILD_TDVPS_ACCESSORS(64, STATE_NON_ARCH, state_non_arch);
+TDX_BUILD_TDVPS_ACCESSORS(8, MANAGEMENT, management);
+
#else
static inline int tdx_module_setup(void) { return -ENODEV; };