x86/virt/tdx: Add SEAMCALL wrappers for TDX flush operations

Intel TDX protects guest VMs from malicious host and certain physical
attacks. The TDX module has the concept of flushing vCPUs. These flushes
include both a flush of the translation caches and also any other state
internal to the TDX module. Before freeing a KeyID, this flush operation
needs to be done. KVM will need to perform the flush on each pCPU
associated with the TD, and also perform a TD scoped operation that checks
if the flush has been done on all vCPU's associated with the TD.

Add a tdh_vp_flush() function to be used to call TDH.VP.FLUSH on each pCPU
associated with the TD during TD teardown. It will also be called when
disabling TDX and during vCPU migration between pCPUs.

Add tdh_mng_vpflushdone() to be used by KVM to call TDH.MNG.VPFLUSHDONE.
KVM will use this during TD teardown to verify that TDH.VP.FLUSH has been
called sufficiently, and advance the state machine that will allow for
reclaiming the TD's KeyID.

Co-developed-by: Sean Christopherson <sean.j.christopherson@intel.com>
Signed-off-by: Sean Christopherson <sean.j.christopherson@intel.com>
Signed-off-by: Isaku Yamahata <isaku.yamahata@intel.com>
Signed-off-by: Kai Huang <kai.huang@intel.com>
Signed-off-by: Rick Edgecombe <rick.p.edgecombe@intel.com>
Reviewed-by: Binbin Wu <binbin.wu@linux.intel.com>
Reviewed-by: Yuan Yao <yuan.yao@intel.com>
Message-ID: <20241203010317.827803-7-rick.p.edgecombe@intel.com>
Acked-by: Dave Hansen <dave.hansen@linux.intel.com>
Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>

diff --git a/arch/x86/include/asm/tdx.h b/arch/x86/include/asm/tdx.h
index 22ffb8dfe994e6e564f1bee36db6019c8ffcacc3..1392f20c3f1d463eeac080a5179eb351b481e5b5 100644 (file)
--- a/arch/x86/include/asm/tdx.h
+++ b/arch/x86/include/asm/tdx.h
@@ -161,6 +161,8 @@ u64 tdh_mng_key_config(struct tdx_td *td);
 u64 tdh_mng_create(struct tdx_td *td, u16 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_vp_flush(struct tdx_vp *vp);
+u64 tdh_mng_vpflushdone(struct tdx_td *td);
 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, u32 x2apicid);

diff --git a/arch/x86/virt/vmx/tdx/tdx.c b/arch/x86/virt/vmx/tdx/tdx.c
index 93150f3c11125c07cd79145121d56a63f0bea19f..369b264f4d9bb29b2484b0e2741a87ecc2176173 100644 (file)
--- a/arch/x86/virt/vmx/tdx/tdx.c
+++ b/arch/x86/virt/vmx/tdx/tdx.c
@@ -1554,6 +1554,26 @@ u64 tdh_mng_rd(struct tdx_td *td, u64 field, u64 *data)
 }
 EXPORT_SYMBOL_GPL(tdh_mng_rd);
 
+u64 tdh_vp_flush(struct tdx_vp *vp)
+{
+       struct tdx_module_args args = {
+               .rcx = tdx_tdvpr_pa(vp),
+       };
+
+       return seamcall(TDH_VP_FLUSH, &args);
+}
+EXPORT_SYMBOL_GPL(tdh_vp_flush);
+
+u64 tdh_mng_vpflushdone(struct tdx_td *td)
+{
+       struct tdx_module_args args = {
+               .rcx = tdx_tdr_pa(td),
+       };
+
+       return seamcall(TDH_MNG_VPFLUSHDONE, &args);
+}
+EXPORT_SYMBOL_GPL(tdh_mng_vpflushdone);
+
 u64 tdh_mng_key_freeid(struct tdx_td *td)
 {
        struct tdx_module_args args = {

diff --git a/arch/x86/virt/vmx/tdx/tdx.h b/arch/x86/virt/vmx/tdx/tdx.h
index aacd38b1298944b2b79000dc032cc23177b3bec6..62cb7832c42d47db0d6d7f2bb78b3185e637a75b 100644 (file)
--- a/arch/x86/virt/vmx/tdx/tdx.h
+++ b/arch/x86/virt/vmx/tdx/tdx.h
@@ -20,6 +20,8 @@
 #define TDH_MNG_KEY_CONFIG             8
 #define TDH_MNG_CREATE                 9
 #define TDH_MNG_RD                     11
+#define TDH_VP_FLUSH                   18
+#define TDH_MNG_VPFLUSHDONE            19
 #define TDH_VP_CREATE                  10
 #define TDH_MNG_KEY_FREEID             20
 #define TDH_MNG_INIT                   21