From mboxrd@z Thu Jan 1 00:00:00 1970 Received: from mail-yw1-f201.google.com (mail-yw1-f201.google.com [209.85.128.201]) (using TLSv1.2 with cipher ECDHE-RSA-AES128-GCM-SHA256 (128/128 bits)) (No client certificate requested) by smtp.subspace.kernel.org (Postfix) with ESMTPS id 9AA391B3921 for ; Mon, 4 Nov 2024 13:32:28 +0000 (UTC) Authentication-Results: smtp.subspace.kernel.org; arc=none smtp.client-ip=209.85.128.201 ARC-Seal:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1730727151; cv=none; b=oeq+rE/Q1onxsQ30WgUIjduuw0U8qr2+SVgoMV43nkjLbvB2uJvY/DexzimKKmXp4gFQylQ0I6bVEJsL1ZYSwQSoXzb9PO2uT35y+cebbw2Ovp2kxdYItUTc72N4wHcs9BBeW815tLorKIEW1TKqA/4sxFshu38xCQNdSqUm7jI= ARC-Message-Signature:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1730727151; c=relaxed/simple; bh=ffOLwbKQb8kwQMl491ZENBc/qOOoZ9iUG3V85WaSIts=; h=Date:In-Reply-To:Mime-Version:References:Message-ID:Subject:From: To:Cc:Content-Type; b=CLm+Msxk/1GNGkBWyb8Oboo35duyifYmTAWymokpb9IJw2qGnxJ4PUOYjser/EeEiBlyLA1vZpFNjcASOzpqETl2XaQU6J4ULWEaW7OqkzjzWwt+wUtice1MINoJD2DT/De3XQY/K+nPGkBOZ4uJjomr8kKW5+b48bR2n8tdoog= ARC-Authentication-Results:i=1; smtp.subspace.kernel.org; dmarc=pass (p=reject dis=none) header.from=google.com; spf=pass smtp.mailfrom=flex--qperret.bounces.google.com; dkim=pass (2048-bit key) header.d=google.com header.i=@google.com header.b=U+4b1qCR; arc=none smtp.client-ip=209.85.128.201 Authentication-Results: smtp.subspace.kernel.org; dmarc=pass (p=reject dis=none) header.from=google.com Authentication-Results: smtp.subspace.kernel.org; spf=pass smtp.mailfrom=flex--qperret.bounces.google.com Authentication-Results: smtp.subspace.kernel.org; dkim=pass (2048-bit key) header.d=google.com header.i=@google.com header.b="U+4b1qCR" Received: by mail-yw1-f201.google.com with SMTP id 00721157ae682-6ea7cfb6e0fso41590037b3.0 for ; Mon, 04 Nov 2024 05:32:28 -0800 (PST) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=google.com; s=20230601; t=1730727147; x=1731331947; darn=lists.linux.dev; h=cc:to:from:subject:message-id:references:mime-version:in-reply-to :date:from:to:cc:subject:date:message-id:reply-to; bh=uWbtmcYWRp1R8Byo4NXAA6u9713XSDAlNYmvHQ2XPgU=; b=U+4b1qCR7xCnLhFm+i3tyUwRKFECCQSlPSBuR6VPFJHwweSaosuBzp/h9IVzZRS7W4 8DIt1gttRGl4SNEPxvLqintbsD7CNrTQ+oby5/CQFFOOtRdvFcOn+QIgeCwDg9UwoW1+ vvTnVM+IlMi1YsHmUw4/WOVXRT9wXw5wSpkzQ7ZQyv4JCcLJKcgYIv9uUEuL6oUoHcN5 cn2D7REft/KmI4pSQCEDv6Rip2aeVlzQUA99gnQDrdlwLNzNCSRqVlYSSLtdaGNO/jWu 6WqDbxUyPZf5PPMxZAMUluj3652390IZvo8JuLfAhaoY1tiHS5SZGgxnXYEsVhX/fbL4 C0Mg== X-Google-DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=1e100.net; s=20230601; t=1730727147; x=1731331947; h=cc:to:from:subject:message-id:references:mime-version:in-reply-to :date:x-gm-message-state:from:to:cc:subject:date:message-id:reply-to; bh=uWbtmcYWRp1R8Byo4NXAA6u9713XSDAlNYmvHQ2XPgU=; b=asmUtIxHn82EYYHQ7d+wA3Qd+hlou2BaDfDDAaziI+uHH3T2E5ugHyP1ZUgWMvZzKC 6IHaeISdlde4DJqa2nwE++rxBduUk4qTaEzbWSUF+/rHFmz497EEOwHAF8sARf+9RwCC 70CpnIW7j026VhLA0kS7jtXSAEflS6LqAstQPeD5uRTPZb/OFERL0aGU2ZP3OK2FvSUt zh9FTMJLHClo4BYEM3q8Tov1JVzYMwaeB/3bi6mc7PbUxSR8F+mKV4Yg0flCdzR7dt8Q +LZfBLqNyJqNMjml3acGHbf1XcJjTMwrXgDHb2MQ2AT3R1K7v4LkoH1ZpYD4F/W0ZHDj U5Pw== X-Forwarded-Encrypted: i=1; AJvYcCULhB1S464lkOLS/6btWa53lReIxrkTBOxWL4CIsOghEgzAW5xbBPhZDCvtdnT00rlVJnm9ZIk=@lists.linux.dev X-Gm-Message-State: AOJu0Yy88cJ+g4UdsSM15aD2AZ5g5iTaLa0D32GfTlCbbHw4/pdQmuMe c/0LDYWsODMYs9W9lFPCPJ068z9OljzydQIeaHj7VZ5JznsG3TfZSrb07IYPgokL46qq/aT+fh+ CQkPC3w== X-Google-Smtp-Source: AGHT+IERD2fe/MuO+b+uqGh1AqVUFKurSVSZTroF+QuBipkZRMH9HgRguuT3lLzoarC3p1VSq8xD3yXmKNOM X-Received: from big-boi.c.googlers.com ([fda3:e722:ac3:cc00:31:98fb:c0a8:129]) (user=qperret job=sendgmr) by 2002:a81:a8c3:0:b0:6e3:d670:f603 with SMTP id 00721157ae682-6e9d8aada53mr4236897b3.3.1730727147304; Mon, 04 Nov 2024 05:32:27 -0800 (PST) Date: Mon, 4 Nov 2024 13:31:54 +0000 In-Reply-To: <20241104133204.85208-1-qperret@google.com> Precedence: bulk X-Mailing-List: kvmarm@lists.linux.dev List-Id: List-Subscribe: List-Unsubscribe: Mime-Version: 1.0 References: <20241104133204.85208-1-qperret@google.com> X-Mailer: git-send-email 2.47.0.163.g1226f6d8fa-goog Message-ID: <20241104133204.85208-9-qperret@google.com> Subject: [PATCH 08/18] KVM: arm64: Introduce pkvm_vcpu_{load,put}() From: Quentin Perret To: Marc Zyngier , Oliver Upton , Joey Gouly , Suzuki K Poulose , Zenghui Yu , Catalin Marinas , Will Deacon Cc: Fuad Tabba , Vincent Donnefort , Sebastian Ene , linux-arm-kernel@lists.infradead.org, kvmarm@lists.linux.dev, linux-kernel@vger.kernel.org Content-Type: text/plain; charset="UTF-8" From: Marc Zyngier Rather than look-up the hyp vCPU on every run hypercall at EL2, introduce a per-CPU 'loaded_hyp_vcpu' tracking variable which is updated by a pair of load/put hypercalls called directly from kvm_arch_vcpu_{load,put}() when pKVM is enabled. Signed-off-by: Marc Zyngier --- arch/arm64/include/asm/kvm_asm.h | 2 ++ arch/arm64/kvm/arm.c | 14 ++++++++ arch/arm64/kvm/hyp/include/nvhe/pkvm.h | 7 ++++ arch/arm64/kvm/hyp/nvhe/hyp-main.c | 47 ++++++++++++++++++++------ arch/arm64/kvm/hyp/nvhe/pkvm.c | 28 +++++++++++++++ arch/arm64/kvm/vgic/vgic-v3.c | 6 ++-- 6 files changed, 92 insertions(+), 12 deletions(-) diff --git a/arch/arm64/include/asm/kvm_asm.h b/arch/arm64/include/asm/kvm_asm.h index 67afac659231..a1c6dbec1871 100644 --- a/arch/arm64/include/asm/kvm_asm.h +++ b/arch/arm64/include/asm/kvm_asm.h @@ -80,6 +80,8 @@ enum __kvm_host_smccc_func { __KVM_HOST_SMCCC_FUNC___pkvm_init_vm, __KVM_HOST_SMCCC_FUNC___pkvm_init_vcpu, __KVM_HOST_SMCCC_FUNC___pkvm_teardown_vm, + __KVM_HOST_SMCCC_FUNC___pkvm_vcpu_load, + __KVM_HOST_SMCCC_FUNC___pkvm_vcpu_put, }; #define DECLARE_KVM_VHE_SYM(sym) extern char sym[] diff --git a/arch/arm64/kvm/arm.c b/arch/arm64/kvm/arm.c index 48cafb65d6ac..2bf168b17a77 100644 --- a/arch/arm64/kvm/arm.c +++ b/arch/arm64/kvm/arm.c @@ -623,12 +623,26 @@ void kvm_arch_vcpu_load(struct kvm_vcpu *vcpu, int cpu) kvm_arch_vcpu_load_debug_state_flags(vcpu); + if (is_protected_kvm_enabled()) { + kvm_call_hyp_nvhe(__pkvm_vcpu_load, + vcpu->kvm->arch.pkvm.handle, + vcpu->vcpu_idx, vcpu->arch.hcr_el2); + kvm_call_hyp(__vgic_v3_restore_vmcr_aprs, + &vcpu->arch.vgic_cpu.vgic_v3); + } + if (!cpumask_test_cpu(cpu, vcpu->kvm->arch.supported_cpus)) vcpu_set_on_unsupported_cpu(vcpu); } void kvm_arch_vcpu_put(struct kvm_vcpu *vcpu) { + if (is_protected_kvm_enabled()) { + kvm_call_hyp(__vgic_v3_save_vmcr_aprs, + &vcpu->arch.vgic_cpu.vgic_v3); + kvm_call_hyp_nvhe(__pkvm_vcpu_put); + } + kvm_arch_vcpu_put_debug_state_flags(vcpu); kvm_arch_vcpu_put_fp(vcpu); if (has_vhe()) diff --git a/arch/arm64/kvm/hyp/include/nvhe/pkvm.h b/arch/arm64/kvm/hyp/include/nvhe/pkvm.h index 24a9a8330d19..6940eb171a52 100644 --- a/arch/arm64/kvm/hyp/include/nvhe/pkvm.h +++ b/arch/arm64/kvm/hyp/include/nvhe/pkvm.h @@ -20,6 +20,12 @@ struct pkvm_hyp_vcpu { /* Backpointer to the host's (untrusted) vCPU instance. */ struct kvm_vcpu *host_vcpu; + + /* + * If this hyp vCPU is loaded, then this is a backpointer to the + * per-cpu pointer tracking us. Otherwise, NULL if not loaded. + */ + struct pkvm_hyp_vcpu **loaded_hyp_vcpu; }; /* @@ -69,5 +75,6 @@ int __pkvm_teardown_vm(pkvm_handle_t handle); struct pkvm_hyp_vcpu *pkvm_load_hyp_vcpu(pkvm_handle_t handle, unsigned int vcpu_idx); void pkvm_put_hyp_vcpu(struct pkvm_hyp_vcpu *hyp_vcpu); +struct pkvm_hyp_vcpu *pkvm_get_loaded_hyp_vcpu(void); #endif /* __ARM64_KVM_NVHE_PKVM_H__ */ diff --git a/arch/arm64/kvm/hyp/nvhe/hyp-main.c b/arch/arm64/kvm/hyp/nvhe/hyp-main.c index fefc89209f9e..6bcdba4fdc76 100644 --- a/arch/arm64/kvm/hyp/nvhe/hyp-main.c +++ b/arch/arm64/kvm/hyp/nvhe/hyp-main.c @@ -139,16 +139,46 @@ static void sync_hyp_vcpu(struct pkvm_hyp_vcpu *hyp_vcpu) host_cpu_if->vgic_lr[i] = hyp_cpu_if->vgic_lr[i]; } +static void handle___pkvm_vcpu_load(struct kvm_cpu_context *host_ctxt) +{ + DECLARE_REG(pkvm_handle_t, handle, host_ctxt, 1); + DECLARE_REG(unsigned int, vcpu_idx, host_ctxt, 2); + DECLARE_REG(u64, hcr_el2, host_ctxt, 3); + struct pkvm_hyp_vcpu *hyp_vcpu; + + if (!is_protected_kvm_enabled()) + return; + + hyp_vcpu = pkvm_load_hyp_vcpu(handle, vcpu_idx); + if (!hyp_vcpu) + return; + + if (pkvm_hyp_vcpu_is_protected(hyp_vcpu)) { + /* Propagate WFx trapping flags */ + hyp_vcpu->vcpu.arch.hcr_el2 &= ~(HCR_TWE | HCR_TWI); + hyp_vcpu->vcpu.arch.hcr_el2 |= hcr_el2 & (HCR_TWE | HCR_TWI); + } +} + +static void handle___pkvm_vcpu_put(struct kvm_cpu_context *host_ctxt) +{ + struct pkvm_hyp_vcpu *hyp_vcpu; + + if (!is_protected_kvm_enabled()) + return; + + hyp_vcpu = pkvm_get_loaded_hyp_vcpu(); + if (hyp_vcpu) + pkvm_put_hyp_vcpu(hyp_vcpu); +} + static void handle___kvm_vcpu_run(struct kvm_cpu_context *host_ctxt) { DECLARE_REG(struct kvm_vcpu *, host_vcpu, host_ctxt, 1); int ret; - host_vcpu = kern_hyp_va(host_vcpu); - if (unlikely(is_protected_kvm_enabled())) { - struct pkvm_hyp_vcpu *hyp_vcpu; - struct kvm *host_kvm; + struct pkvm_hyp_vcpu *hyp_vcpu = pkvm_get_loaded_hyp_vcpu(); /* * KVM (and pKVM) doesn't support SME guests for now, and @@ -161,9 +191,6 @@ static void handle___kvm_vcpu_run(struct kvm_cpu_context *host_ctxt) goto out; } - host_kvm = kern_hyp_va(host_vcpu->kvm); - hyp_vcpu = pkvm_load_hyp_vcpu(host_kvm->arch.pkvm.handle, - host_vcpu->vcpu_idx); if (!hyp_vcpu) { ret = -EINVAL; goto out; @@ -174,12 +201,10 @@ static void handle___kvm_vcpu_run(struct kvm_cpu_context *host_ctxt) ret = __kvm_vcpu_run(&hyp_vcpu->vcpu); sync_hyp_vcpu(hyp_vcpu); - pkvm_put_hyp_vcpu(hyp_vcpu); } else { /* The host is fully trusted, run its vCPU directly. */ - ret = __kvm_vcpu_run(host_vcpu); + ret = __kvm_vcpu_run(kern_hyp_va(host_vcpu)); } - out: cpu_reg(host_ctxt, 1) = ret; } @@ -415,6 +440,8 @@ static const hcall_t host_hcall[] = { HANDLE_FUNC(__pkvm_init_vm), HANDLE_FUNC(__pkvm_init_vcpu), HANDLE_FUNC(__pkvm_teardown_vm), + HANDLE_FUNC(__pkvm_vcpu_load), + HANDLE_FUNC(__pkvm_vcpu_put), }; static void handle_host_hcall(struct kvm_cpu_context *host_ctxt) diff --git a/arch/arm64/kvm/hyp/nvhe/pkvm.c b/arch/arm64/kvm/hyp/nvhe/pkvm.c index 077d4098548d..9ed2b8a63371 100644 --- a/arch/arm64/kvm/hyp/nvhe/pkvm.c +++ b/arch/arm64/kvm/hyp/nvhe/pkvm.c @@ -20,6 +20,12 @@ unsigned int kvm_arm_vmid_bits; unsigned int kvm_host_sve_max_vl; +/* + * The currently loaded hyp vCPU for each physical CPU. Used only when + * protected KVM is enabled, but for both protected and non-protected VMs. + */ +static DEFINE_PER_CPU(struct pkvm_hyp_vcpu *, loaded_hyp_vcpu); + /* * Set trap register values based on features in ID_AA64PFR0. */ @@ -268,15 +274,30 @@ struct pkvm_hyp_vcpu *pkvm_load_hyp_vcpu(pkvm_handle_t handle, struct pkvm_hyp_vcpu *hyp_vcpu = NULL; struct pkvm_hyp_vm *hyp_vm; + /* Cannot load a new vcpu without putting the old one first. */ + if (__this_cpu_read(loaded_hyp_vcpu)) + return NULL; + hyp_spin_lock(&vm_table_lock); hyp_vm = get_vm_by_handle(handle); if (!hyp_vm || hyp_vm->nr_vcpus <= vcpu_idx) goto unlock; hyp_vcpu = hyp_vm->vcpus[vcpu_idx]; + + /* Ensure vcpu isn't loaded on more than one cpu simultaneously. */ + if (unlikely(hyp_vcpu->loaded_hyp_vcpu)) { + hyp_vcpu = NULL; + goto unlock; + } + + hyp_vcpu->loaded_hyp_vcpu = this_cpu_ptr(&loaded_hyp_vcpu); hyp_page_ref_inc(hyp_virt_to_page(hyp_vm)); unlock: hyp_spin_unlock(&vm_table_lock); + + if (hyp_vcpu) + __this_cpu_write(loaded_hyp_vcpu, hyp_vcpu); return hyp_vcpu; } @@ -285,10 +306,17 @@ void pkvm_put_hyp_vcpu(struct pkvm_hyp_vcpu *hyp_vcpu) struct pkvm_hyp_vm *hyp_vm = pkvm_hyp_vcpu_to_hyp_vm(hyp_vcpu); hyp_spin_lock(&vm_table_lock); + hyp_vcpu->loaded_hyp_vcpu = NULL; + __this_cpu_write(loaded_hyp_vcpu, NULL); hyp_page_ref_dec(hyp_virt_to_page(hyp_vm)); hyp_spin_unlock(&vm_table_lock); } +struct pkvm_hyp_vcpu *pkvm_get_loaded_hyp_vcpu(void) +{ + return __this_cpu_read(loaded_hyp_vcpu); +} + static void unpin_host_vcpu(struct kvm_vcpu *host_vcpu) { if (host_vcpu) diff --git a/arch/arm64/kvm/vgic/vgic-v3.c b/arch/arm64/kvm/vgic/vgic-v3.c index b217b256853c..e43a8bb3e6b0 100644 --- a/arch/arm64/kvm/vgic/vgic-v3.c +++ b/arch/arm64/kvm/vgic/vgic-v3.c @@ -734,7 +734,8 @@ void vgic_v3_load(struct kvm_vcpu *vcpu) { struct vgic_v3_cpu_if *cpu_if = &vcpu->arch.vgic_cpu.vgic_v3; - kvm_call_hyp(__vgic_v3_restore_vmcr_aprs, cpu_if); + if (likely(!is_protected_kvm_enabled())) + kvm_call_hyp(__vgic_v3_restore_vmcr_aprs, cpu_if); if (has_vhe()) __vgic_v3_activate_traps(cpu_if); @@ -746,7 +747,8 @@ void vgic_v3_put(struct kvm_vcpu *vcpu) { struct vgic_v3_cpu_if *cpu_if = &vcpu->arch.vgic_cpu.vgic_v3; - kvm_call_hyp(__vgic_v3_save_vmcr_aprs, cpu_if); + if (likely(!is_protected_kvm_enabled())) + kvm_call_hyp(__vgic_v3_save_vmcr_aprs, cpu_if); WARN_ON(vgic_v4_put(vcpu)); if (has_vhe()) -- 2.47.0.163.g1226f6d8fa-goog