From mboxrd@z Thu Jan 1 00:00:00 1970 Received: from smtp.kernel.org (aws-us-west-2-korg-mail-1.web.codeaurora.org [10.30.226.201]) (using TLSv1.2 with cipher ECDHE-RSA-AES256-GCM-SHA384 (256/256 bits)) (No client certificate requested) by smtp.subspace.kernel.org (Postfix) with ESMTPS id 79D0C32144D for ; Thu, 14 Aug 2025 16:12:15 +0000 (UTC) Authentication-Results: smtp.subspace.kernel.org; arc=none smtp.client-ip=10.30.226.201 ARC-Seal:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1755187935; cv=none; b=nZZHqVdzD0qfReqPW8/7JGdAX0VrZZDb97zmP/IGf+P5xtYB976EpUEuJCb9qqWN6EkS35nGAZsA4xm77QevDA/cQoLWLNJfQodl5nmkb3YdmtOs/it8j8rMscD+9kXTf3RHk2WcGAViWrzj4easiwz5wt5jQAWgqR298Z7UQYs= ARC-Message-Signature:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1755187935; c=relaxed/simple; bh=OTb/evqKJ6AB/2g3EfNJNM1rRM0V1acmfrv9iZc89uA=; h=From:To:Cc:Subject:Date:Message-Id:In-Reply-To:References: MIME-Version; b=ZXrmXg8+9QAkEnhsbIlETIYFbw4MDkwWz6rbO2oCpq4DBiGwuM3g9cEVu5okj9nRygHvzt1LLJQ2B5bBwKs/jlUJ8TAXQUXXC00SmXWutXc6pqGWfqSD7OpUKOMsrznRZpPKTW1swaZHXLfYfW5zVIHeWpDoAgszpBRZYADwkAU= ARC-Authentication-Results:i=1; smtp.subspace.kernel.org; dkim=pass (2048-bit key) header.d=kernel.org header.i=@kernel.org header.b=N8SI7xB5; arc=none smtp.client-ip=10.30.226.201 Authentication-Results: smtp.subspace.kernel.org; dkim=pass (2048-bit key) header.d=kernel.org header.i=@kernel.org header.b="N8SI7xB5" Received: by smtp.kernel.org (Postfix) with ESMTPSA id 746C7C4CEED; Thu, 14 Aug 2025 16:12:14 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=kernel.org; s=k20201202; t=1755187934; bh=OTb/evqKJ6AB/2g3EfNJNM1rRM0V1acmfrv9iZc89uA=; h=From:To:Cc:Subject:Date:In-Reply-To:References:From; b=N8SI7xB5mXK8mlliTAMmHFVtXZUg7oq/rDjrPnZr/BTUD1Ev9bD2LVsE/Q4va53rW y87AsDuE6h76MT5n/x3J7etGN9F1WWYFYxnKDDJRtqcuMTMiHLjGiEejzmjl3ALAhC F7NoMYMesk2CYXhwORA9yZfLK6iyZzcdki8aITpaWDr6Rc/udR8zJ0VndDpMmmIibH jLOQeyXEIQPRj0Drce80zz1hMWBe0luF09BBMO1j+6J7CJc0ZRCdOLhJi+YLkrb6hp l9J3DecYA8Hmy7kNgxvBVZwsXA4HZy5ruQIFeksGhAhf7j9rmOe3lcK049o6Icwyl6 vXadw3xou4YKw== From: Sasha Levin To: stable@vger.kernel.org Cc: Sean Christopherson , Sasha Levin Subject: [PATCH 6.16.y 1/6] KVM: x86: Convert vcpu_run()'s immediate exit param into a generic bitmap Date: Thu, 14 Aug 2025 12:12:07 -0400 Message-Id: <20250814161212.2107674-1-sashal@kernel.org> X-Mailer: git-send-email 2.39.5 In-Reply-To: <2025081231-vengeful-creasing-d789@gregkh> References: <2025081231-vengeful-creasing-d789@gregkh> Precedence: bulk X-Mailing-List: stable@vger.kernel.org List-Id: List-Subscribe: List-Unsubscribe: MIME-Version: 1.0 Content-Transfer-Encoding: 8bit From: Sean Christopherson [ Upstream commit 2478b1b220c49d25cb1c3f061ec4f9b351d9a131 ] Convert kvm_x86_ops.vcpu_run()'s "force_immediate_exit" boolean parameter into an a generic bitmap so that similar "take action" information can be passed to vendor code without creating a pile of boolean parameters. This will allow dropping kvm_x86_ops.set_dr6() in favor of a new flag, and will also allow for adding similar functionality for re-loading debugctl in the active VMCS. Opportunistically massage the TDX WARN and comment to prepare for adding more run_flags, all of which are expected to be mutually exclusive with TDX, i.e. should be WARNed on. No functional change intended. Cc: stable@vger.kernel.org Link: https://lore.kernel.org/r/20250610232010.162191-3-seanjc@google.com Signed-off-by: Sean Christopherson Stable-dep-of: 6b1dd26544d0 ("KVM: VMX: Preserve host's DEBUGCTLMSR_FREEZE_IN_SMM while running the guest") Signed-off-by: Sasha Levin --- arch/x86/include/asm/kvm_host.h | 6 +++++- arch/x86/kvm/svm/svm.c | 4 ++-- arch/x86/kvm/vmx/main.c | 6 +++--- arch/x86/kvm/vmx/tdx.c | 18 +++++++++--------- arch/x86/kvm/vmx/vmx.c | 3 ++- arch/x86/kvm/vmx/x86_ops.h | 4 ++-- arch/x86/kvm/x86.c | 11 ++++++++--- 7 files changed, 31 insertions(+), 21 deletions(-) diff --git a/arch/x86/include/asm/kvm_host.h b/arch/x86/include/asm/kvm_host.h index f7af967aa16f..b44f74fed1ac 100644 --- a/arch/x86/include/asm/kvm_host.h +++ b/arch/x86/include/asm/kvm_host.h @@ -1680,6 +1680,10 @@ static inline u16 kvm_lapic_irq_dest_mode(bool dest_mode_logical) return dest_mode_logical ? APIC_DEST_LOGICAL : APIC_DEST_PHYSICAL; } +enum kvm_x86_run_flags { + KVM_RUN_FORCE_IMMEDIATE_EXIT = BIT(0), +}; + struct kvm_x86_ops { const char *name; @@ -1761,7 +1765,7 @@ struct kvm_x86_ops { int (*vcpu_pre_run)(struct kvm_vcpu *vcpu); enum exit_fastpath_completion (*vcpu_run)(struct kvm_vcpu *vcpu, - bool force_immediate_exit); + u64 run_flags); int (*handle_exit)(struct kvm_vcpu *vcpu, enum exit_fastpath_completion exit_fastpath); int (*skip_emulated_instruction)(struct kvm_vcpu *vcpu); diff --git a/arch/x86/kvm/svm/svm.c b/arch/x86/kvm/svm/svm.c index ab9b947dbf4f..83d1b62130b1 100644 --- a/arch/x86/kvm/svm/svm.c +++ b/arch/x86/kvm/svm/svm.c @@ -4389,9 +4389,9 @@ static noinstr void svm_vcpu_enter_exit(struct kvm_vcpu *vcpu, bool spec_ctrl_in guest_state_exit_irqoff(); } -static __no_kcsan fastpath_t svm_vcpu_run(struct kvm_vcpu *vcpu, - bool force_immediate_exit) +static __no_kcsan fastpath_t svm_vcpu_run(struct kvm_vcpu *vcpu, u64 run_flags) { + bool force_immediate_exit = run_flags & KVM_RUN_FORCE_IMMEDIATE_EXIT; struct vcpu_svm *svm = to_svm(vcpu); bool spec_ctrl_intercepted = msr_write_intercepted(vcpu, MSR_IA32_SPEC_CTRL); diff --git a/arch/x86/kvm/vmx/main.c b/arch/x86/kvm/vmx/main.c index d1e02e567b57..fef3e3803707 100644 --- a/arch/x86/kvm/vmx/main.c +++ b/arch/x86/kvm/vmx/main.c @@ -175,12 +175,12 @@ static int vt_vcpu_pre_run(struct kvm_vcpu *vcpu) return vmx_vcpu_pre_run(vcpu); } -static fastpath_t vt_vcpu_run(struct kvm_vcpu *vcpu, bool force_immediate_exit) +static fastpath_t vt_vcpu_run(struct kvm_vcpu *vcpu, u64 run_flags) { if (is_td_vcpu(vcpu)) - return tdx_vcpu_run(vcpu, force_immediate_exit); + return tdx_vcpu_run(vcpu, run_flags); - return vmx_vcpu_run(vcpu, force_immediate_exit); + return vmx_vcpu_run(vcpu, run_flags); } static int vt_handle_exit(struct kvm_vcpu *vcpu, diff --git a/arch/x86/kvm/vmx/tdx.c b/arch/x86/kvm/vmx/tdx.c index ec79aacc446f..d584c0e28692 100644 --- a/arch/x86/kvm/vmx/tdx.c +++ b/arch/x86/kvm/vmx/tdx.c @@ -1025,20 +1025,20 @@ static void tdx_load_host_xsave_state(struct kvm_vcpu *vcpu) DEBUGCTLMSR_FREEZE_PERFMON_ON_PMI | \ DEBUGCTLMSR_FREEZE_IN_SMM) -fastpath_t tdx_vcpu_run(struct kvm_vcpu *vcpu, bool force_immediate_exit) +fastpath_t tdx_vcpu_run(struct kvm_vcpu *vcpu, u64 run_flags) { struct vcpu_tdx *tdx = to_tdx(vcpu); struct vcpu_vt *vt = to_vt(vcpu); /* - * force_immediate_exit requires vCPU entering for events injection with - * an immediately exit followed. But The TDX module doesn't guarantee - * entry, it's already possible for KVM to _think_ it completely entry - * to the guest without actually having done so. - * Since KVM never needs to force an immediate exit for TDX, and can't - * do direct injection, just warn on force_immediate_exit. + * WARN if KVM wants to force an immediate exit, as the TDX module does + * not guarantee entry into the guest, i.e. it's possible for KVM to + * _think_ it completed entry to the guest and forced an immediate exit + * without actually having done so. Luckily, KVM never needs to force + * an immediate exit for TDX (KVM can't do direct event injection, so + * just WARN and continue on. */ - WARN_ON_ONCE(force_immediate_exit); + WARN_ON_ONCE(run_flags); /* * Wait until retry of SEPT-zap-related SEAMCALL completes before @@ -1048,7 +1048,7 @@ fastpath_t tdx_vcpu_run(struct kvm_vcpu *vcpu, bool force_immediate_exit) if (unlikely(READ_ONCE(to_kvm_tdx(vcpu->kvm)->wait_for_sept_zap))) return EXIT_FASTPATH_EXIT_HANDLED; - trace_kvm_entry(vcpu, force_immediate_exit); + trace_kvm_entry(vcpu, run_flags & KVM_RUN_FORCE_IMMEDIATE_EXIT); if (pi_test_on(&vt->pi_desc)) { apic->send_IPI_self(POSTED_INTR_VECTOR); diff --git a/arch/x86/kvm/vmx/vmx.c b/arch/x86/kvm/vmx/vmx.c index 191a9ed0da22..ff33e79f8415 100644 --- a/arch/x86/kvm/vmx/vmx.c +++ b/arch/x86/kvm/vmx/vmx.c @@ -7323,8 +7323,9 @@ static noinstr void vmx_vcpu_enter_exit(struct kvm_vcpu *vcpu, guest_state_exit_irqoff(); } -fastpath_t vmx_vcpu_run(struct kvm_vcpu *vcpu, bool force_immediate_exit) +fastpath_t vmx_vcpu_run(struct kvm_vcpu *vcpu, u64 run_flags) { + bool force_immediate_exit = run_flags & KVM_RUN_FORCE_IMMEDIATE_EXIT; struct vcpu_vmx *vmx = to_vmx(vcpu); unsigned long cr3, cr4; diff --git a/arch/x86/kvm/vmx/x86_ops.h b/arch/x86/kvm/vmx/x86_ops.h index b4596f651232..0b4f5c5558d0 100644 --- a/arch/x86/kvm/vmx/x86_ops.h +++ b/arch/x86/kvm/vmx/x86_ops.h @@ -21,7 +21,7 @@ void vmx_vm_destroy(struct kvm *kvm); int vmx_vcpu_precreate(struct kvm *kvm); int vmx_vcpu_create(struct kvm_vcpu *vcpu); int vmx_vcpu_pre_run(struct kvm_vcpu *vcpu); -fastpath_t vmx_vcpu_run(struct kvm_vcpu *vcpu, bool force_immediate_exit); +fastpath_t vmx_vcpu_run(struct kvm_vcpu *vcpu, u64 run_flags); void vmx_vcpu_free(struct kvm_vcpu *vcpu); void vmx_vcpu_reset(struct kvm_vcpu *vcpu, bool init_event); void vmx_vcpu_load(struct kvm_vcpu *vcpu, int cpu); @@ -133,7 +133,7 @@ void tdx_vcpu_reset(struct kvm_vcpu *vcpu, bool init_event); void tdx_vcpu_free(struct kvm_vcpu *vcpu); void tdx_vcpu_load(struct kvm_vcpu *vcpu, int cpu); int tdx_vcpu_pre_run(struct kvm_vcpu *vcpu); -fastpath_t tdx_vcpu_run(struct kvm_vcpu *vcpu, bool force_immediate_exit); +fastpath_t tdx_vcpu_run(struct kvm_vcpu *vcpu, u64 run_flags); void tdx_prepare_switch_to_guest(struct kvm_vcpu *vcpu); void tdx_vcpu_put(struct kvm_vcpu *vcpu); bool tdx_protected_apic_has_interrupt(struct kvm_vcpu *vcpu); diff --git a/arch/x86/kvm/x86.c b/arch/x86/kvm/x86.c index 93636f77c42d..d0e11b5efcf4 100644 --- a/arch/x86/kvm/x86.c +++ b/arch/x86/kvm/x86.c @@ -10785,6 +10785,7 @@ static int vcpu_enter_guest(struct kvm_vcpu *vcpu) dm_request_for_irq_injection(vcpu) && kvm_cpu_accept_dm_intr(vcpu); fastpath_t exit_fastpath; + u64 run_flags; bool req_immediate_exit = false; @@ -11029,8 +11030,11 @@ static int vcpu_enter_guest(struct kvm_vcpu *vcpu) goto cancel_injection; } - if (req_immediate_exit) + run_flags = 0; + if (req_immediate_exit) { + run_flags |= KVM_RUN_FORCE_IMMEDIATE_EXIT; kvm_make_request(KVM_REQ_EVENT, vcpu); + } fpregs_assert_state_consistent(); if (test_thread_flag(TIF_NEED_FPU_LOAD)) @@ -11067,8 +11071,7 @@ static int vcpu_enter_guest(struct kvm_vcpu *vcpu) WARN_ON_ONCE((kvm_vcpu_apicv_activated(vcpu) != kvm_vcpu_apicv_active(vcpu)) && (kvm_get_apic_mode(vcpu) != LAPIC_MODE_DISABLED)); - exit_fastpath = kvm_x86_call(vcpu_run)(vcpu, - req_immediate_exit); + exit_fastpath = kvm_x86_call(vcpu_run)(vcpu, run_flags); if (likely(exit_fastpath != EXIT_FASTPATH_REENTER_GUEST)) break; @@ -11080,6 +11083,8 @@ static int vcpu_enter_guest(struct kvm_vcpu *vcpu) break; } + run_flags = 0; + /* Note, VM-Exits that go down the "slow" path are accounted below. */ ++vcpu->stat.exits; } -- 2.39.5