Intel TDX protects guest VMs from malicious host and certain physical
attacks. The TDX module has TD scoped and vCPU scoped "metadata fields".
These fields are a bit like VMCS fields, and stored in data structures
maintained by the TDX module. Export 3 SEAMCALLs for use in reading and
writing these fields:
Make tdh_mng_rd() use MNG.VP.RD to read the TD scoped metadata.
Make tdh_vp_rd()/tdh_vp_wr() use TDH.VP.RD/WR to read/write the vCPU
scoped metadata.
KVM will use these by creating inline helpers that target various metadata
sizes. Export the raw SEAMCALL leaf, to avoid exporting the large number
of various sized helpers.
Co-developed-by: Sean Christopherson <sean.j.christopherson@xxxxxxxxx>
Signed-off-by: Sean Christopherson <sean.j.christopherson@xxxxxxxxx>
Signed-off-by: Isaku Yamahata <isaku.yamahata@xxxxxxxxx>
Signed-off-by: Kai Huang <kai.huang@xxxxxxxxx>
Signed-off-by: Rick Edgecombe <rick.p.edgecombe@xxxxxxxxx>
Reviewed-by: Binbin Wu <binbin.wu@xxxxxxxxxxxxxxx>
Reviewed-by: Yuan Yao <yuan.yao@xxxxxxxxx>
---
SEAMCALL RFC:
- Use struct tdx_td and struct tdx_vp
uAPI breakout v2:
- Change to use 'u64' as function parameter to prepare to move
SEAMCALL wrappers to arch/x86. (Kai)
- Split to separate patch
- Move SEAMCALL wrappers from KVM to x86 core;
- Move TDH_xx macros from KVM to x86 core;
- Re-write log
uAPI breakout v1:
- Make argument to C wrapper function struct kvm_tdx * or
struct vcpu_tdx * .(Sean)
- Drop unused helpers (Kai)
- Fix bisectability issues in headers (Kai)
- Updates from seamcall overhaul (Kai)
v19:
- Update the commit message to match the patch by Yuan
- Use seamcall() and seamcall_ret() by paolo
v18:
- removed stub functions for __seamcall{,_ret}()
- Added Reviewed-by Binbin
- Make tdx_seamcall() use struct tdx_module_args instead of taking
each inputs.
---
arch/x86/include/asm/tdx.h | 3 +++
arch/x86/virt/vmx/tdx/tdx.c | 47 +++++++++++++++++++++++++++++++++++++
arch/x86/virt/vmx/tdx/tdx.h | 3 +++
3 files changed, 53 insertions(+)
diff --git a/arch/x86/include/asm/tdx.h b/arch/x86/include/asm/tdx.h
index f6ab8a9ea46b..9bc3c1160d43 100644
--- a/arch/x86/include/asm/tdx.h
+++ b/arch/x86/include/asm/tdx.h
@@ -147,9 +147,12 @@ u64 tdh_vp_addcx(struct tdx_vp *vp, struct page *tdcx_page);
u64 tdh_mng_key_config(struct tdx_td *td);
u64 tdh_mng_create(struct tdx_td *td, u64 hkid);
u64 tdh_vp_create(struct tdx_td *td, struct tdx_vp *vp);
+u64 tdh_mng_rd(struct tdx_td *td, u64 field, u64 *data);
u64 tdh_mng_key_freeid(struct tdx_td *td);
u64 tdh_mng_init(struct tdx_td *td, u64 td_params, u64 *extended_err);
u64 tdh_vp_init(struct tdx_vp *vp, u64 initial_rcx);
+u64 tdh_vp_rd(struct tdx_vp *vp, u64 field, u64 *data);
+u64 tdh_vp_wr(struct tdx_vp *vp, u64 field, u64 data, u64 mask);
u64 tdh_vp_init_apicid(struct tdx_vp *vp, u64 initial_rcx, u32 x2apicid);
u64 tdh_phymem_page_reclaim(struct page *page, u64 *tdx_pt, u64 *tdx_owner, u64 *tdx_size);
u64 tdh_phymem_cache_wb(bool resume);
diff --git a/arch/x86/virt/vmx/tdx/tdx.c b/arch/x86/virt/vmx/tdx/tdx.c
index b2a1ed13d0da..6d35ea5b238f 100644
--- a/arch/x86/virt/vmx/tdx/tdx.c
+++ b/arch/x86/virt/vmx/tdx/tdx.c
@@ -1643,6 +1643,23 @@ u64 tdh_vp_create(struct tdx_td *td, struct tdx_vp *vp)
}
EXPORT_SYMBOL_GPL(tdh_vp_create);
+u64 tdh_mng_rd(struct tdx_td *td, u64 field, u64 *data)
+{
+ struct tdx_module_args args = {
+ .rcx = tdx_tdr_pa(td),
+ .rdx = field,
+ };
+ u64 ret;
+
+ ret = seamcall_ret(TDH_MNG_RD, &args);
+
+ /* R8: Content of the field, or 0 in case of error. */
+ *data = args.r8;
+
+ return ret;
+}
+EXPORT_SYMBOL_GPL(tdh_mng_rd);
+
u64 tdh_mng_key_freeid(struct tdx_td *td)
{
struct tdx_module_args args = {
@@ -1680,6 +1697,36 @@ u64 tdh_vp_init(struct tdx_vp *vp, u64 initial_rcx)
}
EXPORT_SYMBOL_GPL(tdh_vp_init);
+u64 tdh_vp_rd(struct tdx_vp *vp, u64 field, u64 *data)
+{
+ struct tdx_module_args args = {
+ .rcx = tdx_tdvpr_pa(vp),
+ .rdx = field,
+ };
+ u64 ret;
+
+ ret = seamcall_ret(TDH_VP_RD, &args);
+
+ /* R8: Content of the field, or 0 in case of error. */
+ *data = args.r8;
+
+ return ret;
+}
+EXPORT_SYMBOL_GPL(tdh_vp_rd);
+
+u64 tdh_vp_wr(struct tdx_vp *vp, u64 field, u64 data, u64 mask)
+{
+ struct tdx_module_args args = {
+ .rcx = tdx_tdvpr_pa(vp),
+ .rdx = field,
+ .r8 = data,
+ .r9 = mask,
+ };
+
+ return seamcall(TDH_VP_WR, &args);
+}
+EXPORT_SYMBOL_GPL(tdh_vp_wr);
+
u64 tdh_vp_init_apicid(struct tdx_vp *vp, u64 initial_rcx, u32 x2apicid)
{
struct tdx_module_args args = {
diff --git a/arch/x86/virt/vmx/tdx/tdx.h b/arch/x86/virt/vmx/tdx/tdx.h
index 191bdd1e571d..5179fc02d109 100644
--- a/arch/x86/virt/vmx/tdx/tdx.h
+++ b/arch/x86/virt/vmx/tdx/tdx.h
@@ -21,11 +21,13 @@
#define TDH_VP_ADDCX 4
#define TDH_MNG_KEY_CONFIG 8
#define TDH_MNG_CREATE 9
+#define TDH_MNG_RD 11
#define TDH_VP_CREATE 10
#define TDH_MNG_KEY_FREEID 20
#define TDH_MNG_INIT 21
#define TDH_VP_INIT 22
#define TDH_PHYMEM_PAGE_RDMD 24
+#define TDH_VP_RD 26
#define TDH_PHYMEM_PAGE_RECLAIM 28
#define TDH_SYS_KEY_CONFIG 31
#define TDH_SYS_INIT 33
@@ -34,6 +36,7 @@
#define TDH_SYS_TDMR_INIT 36
#define TDH_PHYMEM_CACHE_WB 40
#define TDH_PHYMEM_PAGE_WBINVD 41
+#define TDH_VP_WR 43
#define TDH_SYS_CONFIG 45
/*
--
2.47.1
