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Message-ID: <20251017003244.186495-11-seanjc@google.com>
Date: Thu, 16 Oct 2025 17:32:28 -0700
From: Sean Christopherson <seanjc@...gle.com>
To: Marc Zyngier <maz@...nel.org>, Oliver Upton <oliver.upton@...ux.dev>,
Tianrui Zhao <zhaotianrui@...ngson.cn>, Bibo Mao <maobibo@...ngson.cn>,
Huacai Chen <chenhuacai@...nel.org>, Madhavan Srinivasan <maddy@...ux.ibm.com>,
Anup Patel <anup@...infault.org>, Paul Walmsley <pjw@...nel.org>,
Palmer Dabbelt <palmer@...belt.com>, Albert Ou <aou@...s.berkeley.edu>,
Christian Borntraeger <borntraeger@...ux.ibm.com>, Janosch Frank <frankja@...ux.ibm.com>,
Claudio Imbrenda <imbrenda@...ux.ibm.com>, Sean Christopherson <seanjc@...gle.com>,
Paolo Bonzini <pbonzini@...hat.com>, "Kirill A. Shutemov" <kas@...nel.org>
Cc: linux-arm-kernel@...ts.infradead.org, kvmarm@...ts.linux.dev,
kvm@...r.kernel.org, loongarch@...ts.linux.dev, linux-mips@...r.kernel.org,
linuxppc-dev@...ts.ozlabs.org, kvm-riscv@...ts.infradead.org,
linux-riscv@...ts.infradead.org, x86@...nel.org, linux-coco@...ts.linux.dev,
linux-kernel@...r.kernel.org, Ira Weiny <ira.weiny@...el.com>,
Kai Huang <kai.huang@...el.com>, Michael Roth <michael.roth@....com>,
Yan Zhao <yan.y.zhao@...el.com>, Vishal Annapurve <vannapurve@...gle.com>,
Rick Edgecombe <rick.p.edgecombe@...el.com>, Ackerley Tng <ackerleytng@...gle.com>,
Binbin Wu <binbin.wu@...ux.intel.com>
Subject: [PATCH v3 10/25] 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@...el.com>
Reviewed-by: Binbin Wu <binbin.wu@...ux.intel.com>
Signed-off-by: Sean Christopherson <seanjc@...gle.com>
---
arch/x86/include/asm/kvm_host.h | 4 ++--
arch/x86/kvm/mmu/tdp_mmu.c | 8 ++------
arch/x86/kvm/vmx/tdx.c | 17 ++++++++---------
3 files changed, 12 insertions(+), 17 deletions(-)
diff --git a/arch/x86/include/asm/kvm_host.h b/arch/x86/include/asm/kvm_host.h
index 48598d017d6f..7e92aebd07e8 100644
--- 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 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 9b4006c2120e..c09c25f3f93b 100644
--- 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 abea9b3d08cf..f5cbcbf4e663 100644
--- 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 spte)
{
+ struct page *page = pfn_to_page(spte_to_pfn(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,
--
2.51.0.858.gf9c4a03a3a-goog
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