From patchwork Tue Nov 7 14:55:45 2023 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: Isaku Yamahata X-Patchwork-Id: 13448942 Received: from lindbergh.monkeyblade.net (lindbergh.monkeyblade.net [23.128.96.19]) (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 41881347AC for ; Tue, 7 Nov 2023 14:57:56 +0000 (UTC) Authentication-Results: smtp.subspace.kernel.org; dkim=pass (2048-bit key) header.d=intel.com header.i=@intel.com header.b="jkitLa8V" Received: from mgamail.intel.com (mgamail.intel.com [134.134.136.126]) by lindbergh.monkeyblade.net (Postfix) with ESMTPS id 9EB23122; Tue, 7 Nov 2023 06:57:54 -0800 (PST) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=intel.com; i=@intel.com; q=dns/txt; s=Intel; t=1699369074; x=1730905074; h=from:to:cc:subject:date:message-id:in-reply-to: references:mime-version:content-transfer-encoding; bh=uWltnmYzfs7BObRXLFLXx3+4exGGkdrWvG4bNNpVL6U=; b=jkitLa8V0nYGL6Erw9GvtUg4snkfBdtU2Voig+Iz+pm1B69MfV7LeZXY P6j1xO8FgQ2780cOiLvO7S/R5WJtlbq5sCp3YWzVqe1Bt0KQ2kT3yxCNH cSwC7rO5gqXIJCLftqXxDg5PRvr8Gc6cA7wjV0PucBFlfvunH/wY72lvI pfAix+bEZ5I9bdDP2sIH4QwG3tSO+o9L5uMc/2n+nN48v4FapmxbuUFkw Z/r3QJXOJ5bYedCqkBngnIT4qN9Kip/3Wdx1zASBGvhLvdjmVGF+cT/Su yZlWpDFSwfvWnOmpeAzIjR1ch3Z7IGn5Nm4Gry6HeaJjn6wWzVEJlHfdJ g==; X-IronPort-AV: E=McAfee;i="6600,9927,10887"; a="374555801" X-IronPort-AV: E=Sophos;i="6.03,284,1694761200"; d="scan'208";a="374555801" Received: from orviesa001.jf.intel.com ([10.64.159.141]) by orsmga106.jf.intel.com with ESMTP/TLS/ECDHE-RSA-AES256-GCM-SHA384; 07 Nov 2023 06:57:54 -0800 X-ExtLoop1: 1 X-IronPort-AV: E=Sophos;i="6.03,284,1694761200"; d="scan'208";a="10444072" Received: from ls.sc.intel.com (HELO localhost) ([172.25.112.31]) by smtpauth.intel.com with ESMTP/TLS/ECDHE-RSA-AES256-GCM-SHA384; 07 Nov 2023 06:57:53 -0800 From: isaku.yamahata@intel.com To: kvm@vger.kernel.org, linux-kernel@vger.kernel.org Cc: isaku.yamahata@intel.com, isaku.yamahata@gmail.com, Paolo Bonzini , erdemaktas@google.com, Sean Christopherson , Sagi Shahar , David Matlack , Kai Huang , Zhi Wang , chen.bo@intel.com, hang.yuan@intel.com, tina.zhang@intel.com Subject: [PATCH v17 019/116] KVM: x86, tdx: Make KVM_CAP_MAX_VCPUS backend specific Date: Tue, 7 Nov 2023 06:55:45 -0800 Message-Id: <376bdde3fac2fb13579b33b9db3d3d2bc2774ffa.1699368322.git.isaku.yamahata@intel.com> X-Mailer: git-send-email 2.25.1 In-Reply-To: References: Precedence: bulk X-Mailing-List: kvm@vger.kernel.org List-Id: List-Subscribe: List-Unsubscribe: MIME-Version: 1.0 From: Isaku Yamahata TDX has its own limitation on the maximum number of vcpus that the guest can accommodate. Allow x86 kvm backend to implement its own KVM_ENABLE_CAP handler and implement TDX backend for KVM_CAP_MAX_VCPUS. user space VMM, e.g. qemu, can specify its value instead of KVM_MAX_VCPUS. Signed-off-by: Isaku Yamahata --- arch/x86/include/asm/kvm-x86-ops.h | 2 ++ arch/x86/include/asm/kvm_host.h | 2 ++ arch/x86/kvm/vmx/main.c | 22 ++++++++++++++++++++++ arch/x86/kvm/vmx/tdx.c | 30 ++++++++++++++++++++++++++++++ arch/x86/kvm/vmx/tdx.h | 3 +++ arch/x86/kvm/vmx/x86_ops.h | 5 +++++ arch/x86/kvm/x86.c | 4 ++++ 7 files changed, 68 insertions(+) diff --git a/arch/x86/include/asm/kvm-x86-ops.h b/arch/x86/include/asm/kvm-x86-ops.h index 09abb53d92ea..b7b591f1ff72 100644 --- a/arch/x86/include/asm/kvm-x86-ops.h +++ b/arch/x86/include/asm/kvm-x86-ops.h @@ -21,6 +21,8 @@ KVM_X86_OP(hardware_unsetup) KVM_X86_OP(has_emulated_msr) KVM_X86_OP(vcpu_after_set_cpuid) KVM_X86_OP(is_vm_type_supported) +KVM_X86_OP_OPTIONAL(max_vcpus); +KVM_X86_OP_OPTIONAL(vm_enable_cap) KVM_X86_OP(vm_init) KVM_X86_OP_OPTIONAL(vm_destroy) KVM_X86_OP_OPTIONAL_RET0(vcpu_precreate) diff --git a/arch/x86/include/asm/kvm_host.h b/arch/x86/include/asm/kvm_host.h index 6509e967454a..f240c3d025b1 100644 --- a/arch/x86/include/asm/kvm_host.h +++ b/arch/x86/include/asm/kvm_host.h @@ -1574,7 +1574,9 @@ struct kvm_x86_ops { void (*vcpu_after_set_cpuid)(struct kvm_vcpu *vcpu); bool (*is_vm_type_supported)(unsigned long vm_type); + int (*max_vcpus)(struct kvm *kvm); unsigned int vm_size; + int (*vm_enable_cap)(struct kvm *kvm, struct kvm_enable_cap *cap); int (*vm_init)(struct kvm *kvm); void (*vm_destroy)(struct kvm *kvm); diff --git a/arch/x86/kvm/vmx/main.c b/arch/x86/kvm/vmx/main.c index a95bbd10c3d8..5a857c8defd9 100644 --- a/arch/x86/kvm/vmx/main.c +++ b/arch/x86/kvm/vmx/main.c @@ -6,6 +6,7 @@ #include "nested.h" #include "pmu.h" #include "tdx.h" +#include "tdx_arch.h" static bool enable_tdx __ro_after_init; module_param_named(tdx, enable_tdx, bool, 0444); @@ -16,6 +17,17 @@ static bool vt_is_vm_type_supported(unsigned long type) (enable_tdx && tdx_is_vm_type_supported(type)); } +static int vt_max_vcpus(struct kvm *kvm) +{ + if (!kvm) + return KVM_MAX_VCPUS; + + if (is_td(kvm)) + return min3(kvm->max_vcpus, KVM_MAX_VCPUS, TDX_MAX_VCPUS); + + return kvm->max_vcpus; +} + static int vt_hardware_enable(void) { int ret; @@ -43,6 +55,14 @@ static __init int vt_hardware_setup(void) return 0; } +static int vt_vm_enable_cap(struct kvm *kvm, struct kvm_enable_cap *cap) +{ + if (is_td(kvm)) + return tdx_vm_enable_cap(kvm, cap); + + return -EINVAL; +} + static int vt_vm_init(struct kvm *kvm) { if (is_td(kvm)) @@ -80,7 +100,9 @@ struct kvm_x86_ops vt_x86_ops __initdata = { .has_emulated_msr = vmx_has_emulated_msr, .is_vm_type_supported = vt_is_vm_type_supported, + .max_vcpus = vt_max_vcpus, .vm_size = sizeof(struct kvm_vmx), + .vm_enable_cap = vt_vm_enable_cap, .vm_init = vt_vm_init, .vm_destroy = vmx_vm_destroy, diff --git a/arch/x86/kvm/vmx/tdx.c b/arch/x86/kvm/vmx/tdx.c index f9e80582865d..331fbaa10d46 100644 --- a/arch/x86/kvm/vmx/tdx.c +++ b/arch/x86/kvm/vmx/tdx.c @@ -17,6 +17,36 @@ offsetof(struct tdsysinfo_struct, cpuid_configs)) \ / sizeof(struct tdx_cpuid_config)) +int tdx_vm_enable_cap(struct kvm *kvm, struct kvm_enable_cap *cap) +{ + int r; + + switch (cap->cap) { + case KVM_CAP_MAX_VCPUS: { + if (cap->flags || cap->args[0] == 0) + return -EINVAL; + if (cap->args[0] > KVM_MAX_VCPUS) + return -E2BIG; + if (cap->args[0] > TDX_MAX_VCPUS) + return -E2BIG; + + mutex_lock(&kvm->lock); + if (kvm->created_vcpus) + r = -EBUSY; + else { + kvm->max_vcpus = cap->args[0]; + r = 0; + } + mutex_unlock(&kvm->lock); + break; + } + default: + r = -EINVAL; + break; + } + return r; +} + static int tdx_get_capabilities(struct kvm_tdx_cmd *cmd) { struct kvm_tdx_capabilities __user *user_caps; diff --git a/arch/x86/kvm/vmx/tdx.h b/arch/x86/kvm/vmx/tdx.h index 473013265bd8..22c0b57f69ca 100644 --- a/arch/x86/kvm/vmx/tdx.h +++ b/arch/x86/kvm/vmx/tdx.h @@ -3,6 +3,9 @@ #define __KVM_X86_TDX_H #ifdef CONFIG_INTEL_TDX_HOST + +#include "tdx_ops.h" + struct kvm_tdx { struct kvm kvm; /* TDX specific members follow. */ diff --git a/arch/x86/kvm/vmx/x86_ops.h b/arch/x86/kvm/vmx/x86_ops.h index 6487884a8d8e..ee5d8a38e7f8 100644 --- a/arch/x86/kvm/vmx/x86_ops.h +++ b/arch/x86/kvm/vmx/x86_ops.h @@ -138,11 +138,16 @@ void vmx_setup_mce(struct kvm_vcpu *vcpu); int __init tdx_hardware_setup(struct kvm_x86_ops *x86_ops); bool tdx_is_vm_type_supported(unsigned long type); +int tdx_vm_enable_cap(struct kvm *kvm, struct kvm_enable_cap *cap); int tdx_vm_ioctl(struct kvm *kvm, void __user *argp); #else static inline int tdx_hardware_setup(struct kvm_x86_ops *x86_ops) { return -EOPNOTSUPP; } static inline bool tdx_is_vm_type_supported(unsigned long type) { return false; } +static inline int tdx_vm_enable_cap(struct kvm *kvm, struct kvm_enable_cap *cap) +{ + return -EINVAL; +}; static inline int tdx_vm_ioctl(struct kvm *kvm, void __user *argp) { return -EOPNOTSUPP; } #endif diff --git a/arch/x86/kvm/x86.c b/arch/x86/kvm/x86.c index ced75e9204b9..de6e6462e7f3 100644 --- a/arch/x86/kvm/x86.c +++ b/arch/x86/kvm/x86.c @@ -4694,6 +4694,8 @@ int kvm_vm_ioctl_check_extension(struct kvm *kvm, long ext) break; case KVM_CAP_MAX_VCPUS: r = KVM_MAX_VCPUS; + if (kvm_x86_ops.max_vcpus) + r = static_call(kvm_x86_max_vcpus)(kvm); break; case KVM_CAP_MAX_VCPU_ID: r = KVM_MAX_VCPU_IDS; @@ -6641,6 +6643,8 @@ int kvm_vm_ioctl_enable_cap(struct kvm *kvm, break; default: r = -EINVAL; + if (kvm_x86_ops.vm_enable_cap) + r = static_call(kvm_x86_vm_enable_cap)(kvm, cap); break; } return r;