@@ -74,7 +74,8 @@ u64 make_mmio_spte(struct kvm_vcpu *vcpu, u64 gfn, unsigned int access)
u64 spte = generation_mmio_spte_mask(gen);
u64 gpa = gfn << PAGE_SHIFT;
- WARN_ON_ONCE(!vcpu->kvm->arch.shadow_mmio_value);
+ WARN_ON_ONCE(!vcpu->kvm->arch.shadow_mmio_value &&
+ !kvm_gfn_shared_mask(vcpu->kvm));
access &= shadow_mmio_access_mask;
spte |= vcpu->kvm->arch.shadow_mmio_value | access;
@@ -566,6 +566,10 @@ static void handle_changed_private_spte(struct kvm *kvm, gfn_t gfn,
} else if (was_leaf) {
/* non-present -> non-present doesn't make sense. */
KVM_BUG_ON(!was_present, kvm);
+ /*
+ * Zap private leaf SPTE. Zapping private table is done
+ * below in handle_removed_tdp_mmu_page().
+ */
static_call(kvm_x86_zap_private_spte)(kvm, gfn, level);
static_call(kvm_x86_remove_private_spte)(kvm, gfn, level, old_pfn);
}
@@ -100,6 +100,55 @@ static void vt_vcpu_reset(struct kvm_vcpu *vcpu, bool init_event)
return vmx_vcpu_reset(vcpu, init_event);
}
+static void vt_flush_tlb_all(struct kvm_vcpu *vcpu)
+{
+ if (is_td_vcpu(vcpu))
+ return tdx_flush_tlb(vcpu);
+
+ vmx_flush_tlb_all(vcpu);
+}
+
+static void vt_flush_tlb_current(struct kvm_vcpu *vcpu)
+{
+ if (is_td_vcpu(vcpu))
+ return tdx_flush_tlb(vcpu);
+
+ vmx_flush_tlb_current(vcpu);
+}
+
+static int vt_tlb_remote_flush(struct kvm *kvm)
+{
+ if (is_td(kvm))
+ return tdx_sept_tlb_remote_flush(kvm);
+
+ return vmx_tlb_remote_flush(kvm);
+}
+
+static int vt_tlb_remote_flush_with_range(struct kvm *kvm,
+ struct kvm_tlb_range *range)
+{
+ if (is_td(kvm))
+ return -EOPNOTSUPP; /* fall back to tlb_remote_flush */
+
+ return vmx_tlb_remote_flush_with_range(kvm, range);
+}
+
+static void vt_flush_tlb_gva(struct kvm_vcpu *vcpu, gva_t addr)
+{
+ if (KVM_BUG_ON(is_td_vcpu(vcpu), vcpu->kvm))
+ return;
+
+ vmx_flush_tlb_gva(vcpu, addr);
+}
+
+static void vt_flush_tlb_guest(struct kvm_vcpu *vcpu)
+{
+ if (is_td_vcpu(vcpu))
+ return;
+
+ vmx_flush_tlb_guest(vcpu);
+}
+
static void vt_load_mmu_pgd(struct kvm_vcpu *vcpu, hpa_t root_hpa,
int pgd_level)
{
@@ -176,12 +225,12 @@ struct kvm_x86_ops vt_x86_ops __initdata = {
.set_rflags = vmx_set_rflags,
.get_if_flag = vmx_get_if_flag,
- .flush_tlb_all = vmx_flush_tlb_all,
- .flush_tlb_current = vmx_flush_tlb_current,
- .tlb_remote_flush = vmx_tlb_remote_flush,
- .tlb_remote_flush_with_range = vmx_tlb_remote_flush_with_range,
- .flush_tlb_gva = vmx_flush_tlb_gva,
- .flush_tlb_guest = vmx_flush_tlb_guest,
+ .flush_tlb_all = vt_flush_tlb_all,
+ .flush_tlb_current = vt_flush_tlb_current,
+ .tlb_remote_flush = vt_tlb_remote_flush,
+ .tlb_remote_flush_with_range = vt_tlb_remote_flush_with_range,
+ .flush_tlb_gva = vt_flush_tlb_gva,
+ .flush_tlb_guest = vt_flush_tlb_guest,
.vcpu_pre_run = vmx_vcpu_pre_run,
.vcpu_run = vmx_vcpu_run,
@@ -6,7 +6,9 @@
#include "capabilities.h"
#include "x86_ops.h"
#include "tdx.h"
+#include "vmx.h"
#include "x86.h"
+#include "mmu.h"
#undef pr_fmt
#define pr_fmt(fmt) "tdx: " fmt
@@ -283,10 +285,28 @@ int tdx_vm_init(struct kvm *kvm)
{
struct kvm_tdx *kvm_tdx = to_kvm_tdx(kvm);
+ /*
+ * Because guest TD is protected, VMM can't parse the instruction in TD.
+ * Instead, guest uses MMIO hypercall. For unmodified device driver,
+ * #VE needs to be injected for MMIO and #VE handler in TD converts MMIO
+ * instruction into MMIO hypercall.
+ *
+ * SPTE value for MMIO needs to be setup so that #VE is injected into
+ * TD instead of triggering EPT MISCONFIG.
+ * - RWX=0 so that EPT violation is triggered.
+ * - suppress #VE bit is cleared to inject #VE.
+ */
+ kvm_mmu_set_mmio_spte_value(kvm, 0);
+
+ /* TODO: Enable 2mb and 1gb large page support. */
+ kvm->arch.tdp_max_page_level = PG_LEVEL_4K;
+
/* vCPUs can't be created until after KVM_TDX_INIT_VM. */
kvm->max_vcpus = 0;
kvm_tdx->hkid = -1;
+ spin_lock_init(&kvm_tdx->seamcall_lock);
+
/*
* This function initializes only KVM software construct. It doesn't
* initialize TDX stuff, e.g. TDCS, TDR, TDCX, HKID etc.
@@ -389,6 +409,246 @@ void tdx_load_mmu_pgd(struct kvm_vcpu *vcpu, hpa_t root_hpa, int pgd_level)
td_vmcs_write64(to_tdx(vcpu), SHARED_EPT_POINTER, root_hpa & PAGE_MASK);
}
+static void tdx_unpin_pfn(struct kvm *kvm, kvm_pfn_t pfn)
+{
+ struct page *page = pfn_to_page(pfn);
+
+ put_page(page);
+}
+
+static void __tdx_sept_set_private_spte(struct kvm *kvm, gfn_t gfn,
+ enum pg_level level, kvm_pfn_t pfn)
+{
+ struct kvm_tdx *kvm_tdx = to_kvm_tdx(kvm);
+ hpa_t hpa = pfn_to_hpa(pfn);
+ gpa_t gpa = gfn_to_gpa(gfn);
+ struct tdx_module_output out;
+ u64 err;
+
+ if (WARN_ON_ONCE(is_error_noslot_pfn(pfn) ||
+ !kvm_pfn_to_refcounted_page(pfn)))
+ return;
+
+ /* TODO: handle large pages. */
+ if (KVM_BUG_ON(level != PG_LEVEL_4K, kvm))
+ return;
+
+ /* To prevent page migration, do nothing on mmu notifier. */
+ get_page(pfn_to_page(pfn));
+
+ if (likely(is_td_finalized(kvm_tdx))) {
+ err = tdh_mem_page_aug(kvm_tdx->tdr.pa, gpa, hpa, &out);
+ if (KVM_BUG_ON(err, kvm)) {
+ pr_tdx_error(TDH_MEM_PAGE_AUG, err, &out);
+ put_page(pfn_to_page(pfn));
+ }
+ return;
+ }
+}
+
+static void tdx_sept_set_private_spte(struct kvm *kvm, gfn_t gfn,
+ enum pg_level level, kvm_pfn_t pfn)
+{
+ struct kvm_tdx *kvm_tdx = to_kvm_tdx(kvm);
+
+ spin_lock(&kvm_tdx->seamcall_lock);
+ __tdx_sept_set_private_spte(kvm, gfn, level, pfn);
+ spin_unlock(&kvm_tdx->seamcall_lock);
+}
+
+static void tdx_sept_drop_private_spte(struct kvm *kvm, gfn_t gfn,
+ enum pg_level level, kvm_pfn_t pfn)
+{
+ int tdx_level = pg_level_to_tdx_sept_level(level);
+ struct kvm_tdx *kvm_tdx = to_kvm_tdx(kvm);
+ gpa_t gpa = gfn_to_gpa(gfn);
+ hpa_t hpa = pfn_to_hpa(pfn);
+ hpa_t hpa_with_hkid;
+ struct tdx_module_output out;
+ u64 err = 0;
+
+ /* TODO: handle large pages. */
+ if (KVM_BUG_ON(level != PG_LEVEL_4K, kvm))
+ return;
+
+ spin_lock(&kvm_tdx->seamcall_lock);
+ if (is_hkid_assigned(kvm_tdx)) {
+ err = tdh_mem_page_remove(kvm_tdx->tdr.pa, gpa, tdx_level, &out);
+ if (KVM_BUG_ON(err, kvm)) {
+ pr_tdx_error(TDH_MEM_PAGE_REMOVE, err, &out);
+ goto unlock;
+ }
+
+ hpa_with_hkid = set_hkid_to_hpa(hpa, (u16)kvm_tdx->hkid);
+ err = tdh_phymem_page_wbinvd(hpa_with_hkid);
+ if (WARN_ON_ONCE(err)) {
+ pr_tdx_error(TDH_PHYMEM_PAGE_WBINVD, err, NULL);
+ goto unlock;
+ }
+ } else
+ /*
+ * The HKID assigned to this TD was already freed and cache
+ * was already flushed. We don't have to flush again.
+ */
+ err = tdx_reclaim_page((unsigned long)__va(hpa), hpa, false, 0);
+
+unlock:
+ spin_unlock(&kvm_tdx->seamcall_lock);
+
+ if (!err)
+ tdx_unpin_pfn(kvm, pfn);
+}
+
+static int tdx_sept_link_private_spt(struct kvm *kvm, gfn_t gfn,
+ enum pg_level level, void *private_spt)
+{
+ int tdx_level = pg_level_to_tdx_sept_level(level);
+ struct kvm_tdx *kvm_tdx = to_kvm_tdx(kvm);
+ gpa_t gpa = gfn_to_gpa(gfn);
+ hpa_t hpa = __pa(private_spt);
+ struct tdx_module_output out;
+ u64 err;
+
+ spin_lock(&kvm_tdx->seamcall_lock);
+ err = tdh_mem_sept_add(kvm_tdx->tdr.pa, gpa, tdx_level, hpa, &out);
+ spin_unlock(&kvm_tdx->seamcall_lock);
+ if (KVM_BUG_ON(err, kvm)) {
+ pr_tdx_error(TDH_MEM_SEPT_ADD, err, &out);
+ return -EIO;
+ }
+
+ return 0;
+}
+
+static void tdx_sept_zap_private_spte(struct kvm *kvm, gfn_t gfn,
+ enum pg_level level)
+{
+ int tdx_level = pg_level_to_tdx_sept_level(level);
+ struct kvm_tdx *kvm_tdx = to_kvm_tdx(kvm);
+ gpa_t gpa = gfn_to_gpa(gfn);
+ struct tdx_module_output out;
+ u64 err;
+
+ /* For now large page isn't supported yet. */
+ WARN_ON_ONCE(level != PG_LEVEL_4K);
+ spin_lock(&kvm_tdx->seamcall_lock);
+ err = tdh_mem_range_block(kvm_tdx->tdr.pa, gpa, tdx_level, &out);
+ spin_unlock(&kvm_tdx->seamcall_lock);
+ if (KVM_BUG_ON(err, kvm))
+ pr_tdx_error(TDH_MEM_RANGE_BLOCK, err, &out);
+}
+
+/*
+ * TLB shoot down procedure:
+ * There is a global epoch counter and each vcpu has local epoch counter.
+ * - TDH.MEM.RANGE.BLOCK(TDR. level, range) on one vcpu
+ * This blocks the subsequenct creation of TLB translation on that range.
+ * This corresponds to clear the present bit(all RXW) in EPT entry
+ * - TDH.MEM.TRACK(TDR): advances the epoch counter which is global.
+ * - IPI to remote vcpus
+ * - TDExit and re-entry with TDH.VP.ENTER on remote vcpus
+ * - On re-entry, TDX module compares the local epoch counter with the global
+ * epoch counter. If the local epoch counter is older than the global epoch
+ * counter, update the local epoch counter and flushes TLB.
+ */
+static void tdx_track(struct kvm_tdx *kvm_tdx)
+{
+ u64 err;
+
+ KVM_BUG_ON(!is_hkid_assigned(kvm_tdx), &kvm_tdx->kvm);
+ /* If TD isn't finalized, it's before any vcpu running. */
+ if (unlikely(!is_td_finalized(kvm_tdx)))
+ return;
+
+ /*
+ * tdx_flush_tlb() waits for this function to issue TDH.MEM.TRACK() by
+ * the counter. The counter is used instead of bool because multiple
+ * TDH_MEM_TRACK() can be issued concurrently by multiple vcpus.
+ */
+ atomic_inc(&kvm_tdx->tdh_mem_track);
+ /*
+ * KVM_REQ_TLB_FLUSH waits for the empty IPI handler, ack_flush(), with
+ * KVM_REQUEST_WAIT.
+ */
+ kvm_make_all_cpus_request(&kvm_tdx->kvm, KVM_REQ_TLB_FLUSH);
+
+ spin_lock(&kvm_tdx->seamcall_lock);
+ err = tdh_mem_track(kvm_tdx->tdr.pa);
+ spin_unlock(&kvm_tdx->seamcall_lock);
+
+ /* Release remote vcpu waiting for TDH.MEM.TRACK in tdx_flush_tlb(). */
+ atomic_dec(&kvm_tdx->tdh_mem_track);
+
+ if (KVM_BUG_ON(err, &kvm_tdx->kvm))
+ pr_tdx_error(TDH_MEM_TRACK, err, NULL);
+
+}
+
+static int tdx_sept_free_private_spt(struct kvm *kvm, gfn_t gfn,
+ enum pg_level level, void *private_spt)
+{
+ struct kvm_tdx *kvm_tdx = to_kvm_tdx(kvm);
+ int ret;
+
+ /*
+ * free_private_spt() is (obviously) called when a shadow page is being
+ * zapped. KVM doesn't (yet) zap private SPs while the TD is active.
+ * Note: This function is for private shadow page. Not for private
+ * guest page. private guest page can be zapped during TD is active.
+ * shared <-> private conversion and slot move/deletion.
+ *
+ * TODO: large page support. If large page is supported, S-EPT page
+ * can be freed when promoting 4K page to 2M/1G page during TD running.
+ * In such case, flush cache and TDH.PAGE.RECLAIM.
+ */
+ if (KVM_BUG_ON(is_hkid_assigned(to_kvm_tdx(kvm)), kvm))
+ return -EINVAL;
+
+ /*
+ * The HKID assigned to this TD was already freed and cache was
+ * already flushed. We don't have to flush again.
+ */
+ spin_lock(&kvm_tdx->seamcall_lock);
+ ret = tdx_reclaim_page((unsigned long)private_spt, __pa(private_spt), false, 0);
+ spin_unlock(&kvm_tdx->seamcall_lock);
+
+ return ret;
+}
+
+int tdx_sept_tlb_remote_flush(struct kvm *kvm)
+{
+ struct kvm_tdx *kvm_tdx;
+
+ if (!is_td(kvm))
+ return -EOPNOTSUPP;
+
+ kvm_tdx = to_kvm_tdx(kvm);
+ if (is_hkid_assigned(kvm_tdx))
+ tdx_track(kvm_tdx);
+
+ return 0;
+}
+
+static void tdx_sept_remove_private_spte(struct kvm *kvm, gfn_t gfn,
+ enum pg_level level, kvm_pfn_t pfn)
+{
+ /*
+ * TDX requires TLB tracking before dropping private page. Do
+ * it here, although it is also done later.
+ * If hkid isn't assigned, the guest is destroying and no vcpu
+ * runs further. TLB shootdown isn't needed.
+ *
+ * TODO: implement with_range version for optimization.
+ * kvm_flush_remote_tlbs_with_address(kvm, gfn, 1);
+ * => tdx_sept_tlb_remote_flush_with_range(kvm, gfn,
+ * KVM_PAGES_PER_HPAGE(level));
+ */
+ if (is_hkid_assigned(to_kvm_tdx(kvm)))
+ kvm_flush_remote_tlbs(kvm);
+
+ tdx_sept_drop_private_spte(kvm, gfn, level, pfn);
+}
+
int tdx_dev_ioctl(void __user *argp)
{
struct kvm_tdx_capabilities __user *user_caps;
@@ -801,6 +1061,25 @@ static int tdx_td_init(struct kvm *kvm, struct kvm_tdx_cmd *cmd)
return ret;
}
+void tdx_flush_tlb(struct kvm_vcpu *vcpu)
+{
+ struct kvm_tdx *kvm_tdx = to_kvm_tdx(vcpu->kvm);
+ struct kvm_mmu *mmu = vcpu->arch.mmu;
+ u64 root_hpa = mmu->root.hpa;
+
+ /* Flush the shared EPTP, if it's valid. */
+ if (VALID_PAGE(root_hpa))
+ ept_sync_context(construct_eptp(vcpu, root_hpa,
+ mmu->root_role.level));
+
+ /*
+ * See tdx_track(). Wait for tlb shootdown initiater to finish
+ * TDH_MEM_TRACK() so that TLB is flushed on the next TDENTER.
+ */
+ while (atomic_read(&kvm_tdx->tdh_mem_track))
+ cpu_relax();
+}
+
int tdx_vm_ioctl(struct kvm *kvm, void __user *argp)
{
struct kvm_tdx_cmd tdx_cmd;
@@ -1010,8 +1289,16 @@ int __init tdx_hardware_setup(struct kvm_x86_ops *x86_ops)
if (!r)
r = tdx_module_setup();
vmxoff_all();
+ if (r)
+ return r;
- return r;
+ x86_ops->link_private_spt = tdx_sept_link_private_spt;
+ x86_ops->free_private_spt = tdx_sept_free_private_spt;
+ x86_ops->set_private_spte = tdx_sept_set_private_spte;
+ x86_ops->remove_private_spte = tdx_sept_remove_private_spte;
+ x86_ops->zap_private_spte = tdx_sept_zap_private_spte;
+
+ return 0;
}
void tdx_hardware_unsetup(void)
@@ -24,8 +24,23 @@ struct kvm_tdx {
int hkid;
bool finalized;
+ atomic_t tdh_mem_track;
u64 tsc_offset;
+
+ /*
+ * Some SEAMCALLs try to lock TD resources (e.g. Secure-EPT) they use or
+ * update. If TDX module fails to obtain the lock, it returns
+ * TDX_OPERAND_BUSY error without spinning. It's VMM/OS responsibility
+ * to retry or guarantee no contention because TDX module has the
+ * restriction on cpu cycles it can spend and VMM/OS knows better
+ * vcpu scheduling.
+ *
+ * TDP MMU uses read lock of kvm.arch.mmu_lock so TDP MMU code can be
+ * run concurrently with multiple vCPUs. Lock to prevent seamcalls from
+ * running concurrently when TDP MMU is enabled.
+ */
+ spinlock_t seamcall_lock;
};
struct vcpu_tdx {
@@ -181,6 +196,12 @@ static __always_inline u64 td_tdcs_exec_read64(struct kvm_tdx *kvm_tdx, u32 fiel
return out.r8;
}
+static __always_inline int pg_level_to_tdx_sept_level(enum pg_level level)
+{
+ WARN_ON_ONCE(level == PG_LEVEL_NONE);
+ return level - 1;
+}
+
#else
struct kvm_tdx {
struct kvm kvm;
@@ -151,6 +151,8 @@ void tdx_vcpu_reset(struct kvm_vcpu *vcpu, bool init_event);
int tdx_vm_ioctl(struct kvm *kvm, void __user *argp);
int tdx_vcpu_ioctl(struct kvm_vcpu *vcpu, void __user *argp);
+void tdx_flush_tlb(struct kvm_vcpu *vcpu);
+int tdx_sept_tlb_remote_flush(struct kvm *kvm);
void tdx_load_mmu_pgd(struct kvm_vcpu *vcpu, hpa_t root_hpa, int root_level);
#else
static inline int tdx_hardware_setup(struct kvm_x86_ops *x86_ops) { return 0; }
@@ -171,6 +173,8 @@ static inline void tdx_vcpu_reset(struct kvm_vcpu *vcpu, bool init_event) {}
static inline int tdx_vm_ioctl(struct kvm *kvm, void __user *argp) { return -EOPNOTSUPP; }
static inline int tdx_vcpu_ioctl(struct kvm_vcpu *vcpu, void __user *argp) { return -EOPNOTSUPP; }
+static inline void tdx_flush_tlb(struct kvm_vcpu *vcpu) {}
+static inline int tdx_sept_tlb_remote_flush(struct kvm *kvm) { return 0; }
static inline void tdx_load_mmu_pgd(struct kvm_vcpu *vcpu, hpa_t root_hpa, int root_level) {}
#endif