KVM: x86/mmu: Drop the return code from kvm_x86_ops.remove_external_spte()

Drop the return code from kvm_x86_ops.remove_external_spte(), a.k.a.
tdx_sept_remove_private_spte(), as KVM simply does a KVM_BUG_ON() failure,
and that KVM_BUG_ON() is redundant since all error paths in TDX also do a
KVM_BUG_ON().

Opportunistically pass the spte instead of the pfn, as the API is clearly
about removing an spte.

Suggested-by: Rick Edgecombe <rick.p.edgecombe@intel.com>
Reviewed-by: Binbin Wu <binbin.wu@linux.intel.com>
Reviewed-by: Kai Huang <kai.huang@intel.com>
Reviewed-by: Yan Zhao <yan.y.zhao@intel.com>
Tested-by: Yan Zhao <yan.y.zhao@intel.com>
Tested-by: Kai Huang <kai.huang@intel.com>
Link: https://patch.msgid.link/20251030200951.3402865-12-seanjc@google.com
Signed-off-by: Sean Christopherson <seanjc@google.com>

diff --git a/arch/x86/include/asm/kvm_host.h b/arch/x86/include/asm/kvm_host.h
index 48598d017d6f3f07263a2ffffe670be2658eb9cb..b5867f8fe6ce57a9be71aa3508d72f24298d6d3d 100644 (file)
--- a/arch/x86/include/asm/kvm_host.h
+++ b/arch/x86/include/asm/kvm_host.h
@@ -1855,8 +1855,8 @@ struct kvm_x86_ops {
                                 void *external_spt);
 
        /* Update external page table from spte getting removed, and flush TLB. */
-       int (*remove_external_spte)(struct kvm *kvm, gfn_t gfn, enum pg_level level,
-                                   kvm_pfn_t pfn_for_gfn);
+       void (*remove_external_spte)(struct kvm *kvm, gfn_t gfn, enum pg_level level,
+                                    u64 mirror_spte);
 
        bool (*has_wbinvd_exit)(void);
 

diff --git a/arch/x86/kvm/mmu/tdp_mmu.c b/arch/x86/kvm/mmu/tdp_mmu.c
index e735d2f8367b4d517697a31346985fc3e951ec5d..e1a96e9ea1bbc9ab7b9a138dd3ac89a72ebf8cba 100644 (file)
--- a/arch/x86/kvm/mmu/tdp_mmu.c
+++ b/arch/x86/kvm/mmu/tdp_mmu.c
@@ -362,9 +362,6 @@ static void tdp_mmu_unlink_sp(struct kvm *kvm, struct kvm_mmu_page *sp)
 static void remove_external_spte(struct kvm *kvm, gfn_t gfn, u64 old_spte,
                                 int level)
 {
-       kvm_pfn_t old_pfn = spte_to_pfn(old_spte);
-       int ret;
-
        /*
         * External (TDX) SPTEs are limited to PG_LEVEL_4K, and external
         * PTs are removed in a special order, involving free_external_spt().
@@ -377,9 +374,8 @@ static void remove_external_spte(struct kvm *kvm, gfn_t gfn, u64 old_spte,
 
        /* Zapping leaf spte is allowed only when write lock is held. */
        lockdep_assert_held_write(&kvm->mmu_lock);
-       /* Because write lock is held, operation should success. */
-       ret = kvm_x86_call(remove_external_spte)(kvm, gfn, level, old_pfn);
-       KVM_BUG_ON(ret, kvm);
+
+       kvm_x86_call(remove_external_spte)(kvm, gfn, level, old_spte);
 }
 
 /**

diff --git a/arch/x86/kvm/vmx/tdx.c b/arch/x86/kvm/vmx/tdx.c
index 667cd089eec8d07588d025dee63f942e657c9a5c..247c35164565f22a2706cd8cfbdc8b4b32e9ea94 100644 (file)
--- a/arch/x86/kvm/vmx/tdx.c
+++ b/arch/x86/kvm/vmx/tdx.c
@@ -1806,12 +1806,12 @@ static int tdx_sept_free_private_spt(struct kvm *kvm, gfn_t gfn,
        return tdx_reclaim_page(virt_to_page(private_spt));
 }
 
-static int tdx_sept_remove_private_spte(struct kvm *kvm, gfn_t gfn,
-                                       enum pg_level level, kvm_pfn_t pfn)
+static void tdx_sept_remove_private_spte(struct kvm *kvm, gfn_t gfn,
+                                        enum pg_level level, u64 mirror_spte)
 {
+       struct page *page = pfn_to_page(spte_to_pfn(mirror_spte));
        int tdx_level = pg_level_to_tdx_sept_level(level);
        struct kvm_tdx *kvm_tdx = to_kvm_tdx(kvm);
-       struct page *page = pfn_to_page(pfn);
        gpa_t gpa = gfn_to_gpa(gfn);
        u64 err, entry, level_state;
        int ret;
@@ -1822,15 +1822,15 @@ static int tdx_sept_remove_private_spte(struct kvm *kvm, gfn_t gfn,
         * there can't be anything populated in the private EPT.
         */
        if (KVM_BUG_ON(!is_hkid_assigned(to_kvm_tdx(kvm)), kvm))
-               return -EIO;
+               return;
 
        /* TODO: handle large pages. */
        if (KVM_BUG_ON(level != PG_LEVEL_4K, kvm))
-               return -EIO;
+               return;
 
        ret = tdx_sept_zap_private_spte(kvm, gfn, level, page);
        if (ret <= 0)
-               return ret;
+               return;
 
        /*
         * TDX requires TLB tracking before dropping private page.  Do
@@ -1859,17 +1859,16 @@ static int tdx_sept_remove_private_spte(struct kvm *kvm, gfn_t gfn,
 
        if (KVM_BUG_ON(err, kvm)) {
                pr_tdx_error_2(TDH_MEM_PAGE_REMOVE, err, entry, level_state);
-               return -EIO;
+               return;
        }
 
        err = tdh_phymem_page_wbinvd_hkid((u16)kvm_tdx->hkid, page);
        if (KVM_BUG_ON(err, kvm)) {
                pr_tdx_error(TDH_PHYMEM_PAGE_WBINVD, err);
-               return -EIO;
+               return;
        }
 
        tdx_quirk_reset_page(page);
-       return 0;
 }
 
 void tdx_deliver_interrupt(struct kvm_lapic *apic, int delivery_mode,