linux-kernel - [PATCH 09/25] KVM: TDX: Get system-wide info about TDX module on initialization

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Message-Id: <20240812224820.34826-10-rick.p.edgecombe@intel.com>
Date: Mon, 12 Aug 2024 15:48:04 -0700
From: Rick Edgecombe <rick.p.edgecombe@...el.com>
To: seanjc@...gle.com,
	pbonzini@...hat.com,
	kvm@...r.kernel.org
Cc: kai.huang@...el.com,
	isaku.yamahata@...il.com,
	tony.lindgren@...ux.intel.com,
	xiaoyao.li@...el.com,
	linux-kernel@...r.kernel.org,
	rick.p.edgecombe@...el.com,
	Isaku Yamahata <isaku.yamahata@...el.com>,
	Binbin Wu <binbin.wu@...ux.intel.com>
Subject: [PATCH 09/25] KVM: TDX: Get system-wide info about TDX module on initialization

From: Isaku Yamahata <isaku.yamahata@...el.com>

TDX KVM needs system-wide information about the TDX module, store it in
struct tdx_info.  Release the allocated memory on module unloading by
hardware_unsetup() callback.

Signed-off-by: Isaku Yamahata <isaku.yamahata@...el.com>
Signed-off-by: Rick Edgecombe <rick.p.edgecombe@...el.com>
Reviewed-by: Binbin Wu <binbin.wu@...ux.intel.com>
---
uAPI breakout v1:
 - Mention about hardware_unsetup(). (Binbin)
 - Added Reviewed-by. (Binbin)
 - Eliminated tdx_md_read(). (Kai)
 - Include "x86_ops.h" to tdx.c as the patch to initialize TDX module
   doesn't include it anymore.
 - Introduce tdx_vm_ioctl() as the first tdx func in x86_ops.h

v19:
 - Added features0
 - Use tdx_sys_metadata_read()
 - Fix error recovery path by Yuan

Change v18:
 - Newly Added
---
 arch/x86/include/uapi/asm/kvm.h | 28 +++++++++++++
 arch/x86/kvm/vmx/tdx.c          | 70 +++++++++++++++++++++++++++++++++
 2 files changed, 98 insertions(+)

diff --git a/arch/x86/include/uapi/asm/kvm.h b/arch/x86/include/uapi/asm/kvm.h
index d91f1bad800e..47caf508cca7 100644
--- a/arch/x86/include/uapi/asm/kvm.h
+++ b/arch/x86/include/uapi/asm/kvm.h
@@ -952,4 +952,32 @@ struct kvm_tdx_cmd {
 	__u64 hw_error;
 };
 
+#define KVM_TDX_CPUID_NO_SUBLEAF	((__u32)-1)
+
+struct kvm_tdx_cpuid_config {
+	__u32 leaf;
+	__u32 sub_leaf;
+	__u32 eax;
+	__u32 ebx;
+	__u32 ecx;
+	__u32 edx;
+};
+
+/* supported_gpaw */
+#define TDX_CAP_GPAW_48	(1 << 0)
+#define TDX_CAP_GPAW_52	(1 << 1)
+
+struct kvm_tdx_capabilities {
+	__u64 attrs_fixed0;
+	__u64 attrs_fixed1;
+	__u64 xfam_fixed0;
+	__u64 xfam_fixed1;
+	__u32 supported_gpaw;
+	__u32 padding;
+	__u64 reserved[251];
+
+	__u32 nr_cpuid_configs;
+	struct kvm_tdx_cpuid_config cpuid_configs[];
+};
+
 #endif /* _ASM_X86_KVM_H */
diff --git a/arch/x86/kvm/vmx/tdx.c b/arch/x86/kvm/vmx/tdx.c
index de14e80d8f3a..90b44ebaf864 100644
--- a/arch/x86/kvm/vmx/tdx.c
+++ b/arch/x86/kvm/vmx/tdx.c
@@ -3,6 +3,7 @@
 #include <asm/tdx.h>
 #include "capabilities.h"
 #include "x86_ops.h"
+#include "mmu.h"
 #include "tdx.h"
 
 #undef pr_fmt
@@ -30,6 +31,72 @@ static void __used tdx_guest_keyid_free(int keyid)
 	ida_free(&tdx_guest_keyid_pool, keyid);
 }
 
+static int tdx_get_capabilities(struct kvm_tdx_cmd *cmd)
+{
+	const struct tdx_sysinfo_td_conf *td_conf = &tdx_sysinfo->td_conf;
+	struct kvm_tdx_capabilities __user *user_caps;
+	struct kvm_tdx_capabilities *caps = NULL;
+	int i, ret = 0;
+
+	/* flags is reserved for future use */
+	if (cmd->flags)
+		return -EINVAL;
+
+	caps = kmalloc(sizeof(*caps), GFP_KERNEL);
+	if (!caps)
+		return -ENOMEM;
+
+	user_caps = u64_to_user_ptr(cmd->data);
+	if (copy_from_user(caps, user_caps, sizeof(*caps))) {
+		ret = -EFAULT;
+		goto out;
+	}
+
+	if (caps->nr_cpuid_configs < td_conf->num_cpuid_config) {
+		ret = -E2BIG;
+		goto out;
+	}
+
+	*caps = (struct kvm_tdx_capabilities) {
+		.attrs_fixed0 = td_conf->attributes_fixed0,
+		.attrs_fixed1 = td_conf->attributes_fixed1,
+		.xfam_fixed0 = td_conf->xfam_fixed0,
+		.xfam_fixed1 = td_conf->xfam_fixed1,
+		.supported_gpaw = TDX_CAP_GPAW_48 |
+		((kvm_host.maxphyaddr >= 52 &&
+		  cpu_has_vmx_ept_5levels()) ? TDX_CAP_GPAW_52 : 0),
+		.nr_cpuid_configs = td_conf->num_cpuid_config,
+		.padding = 0,
+	};
+
+	if (copy_to_user(user_caps, caps, sizeof(*caps))) {
+		ret = -EFAULT;
+		goto out;
+	}
+
+	for (i = 0; i < td_conf->num_cpuid_config; i++) {
+		struct kvm_tdx_cpuid_config cpuid_config = {
+			.leaf = (u32)td_conf->cpuid_config_leaves[i],
+			.sub_leaf = td_conf->cpuid_config_leaves[i] >> 32,
+			.eax = (u32)td_conf->cpuid_config_values[i].eax_ebx,
+			.ebx = td_conf->cpuid_config_values[i].eax_ebx >> 32,
+			.ecx = (u32)td_conf->cpuid_config_values[i].ecx_edx,
+			.edx = td_conf->cpuid_config_values[i].ecx_edx >> 32,
+		};
+
+		if (copy_to_user(&(user_caps->cpuid_configs[i]), &cpuid_config,
+					sizeof(struct kvm_tdx_cpuid_config))) {
+			ret = -EFAULT;
+			break;
+		}
+	}
+
+out:
+	/* kfree() accepts NULL. */
+	kfree(caps);
+	return ret;
+}
+
 int tdx_vm_ioctl(struct kvm *kvm, void __user *argp)
 {
 	struct kvm_tdx_cmd tdx_cmd;
@@ -48,6 +115,9 @@ int tdx_vm_ioctl(struct kvm *kvm, void __user *argp)
 	mutex_lock(&kvm->lock);
 
 	switch (tdx_cmd.id) {
+	case KVM_TDX_CAPABILITIES:
+		r = tdx_get_capabilities(&tdx_cmd);
+		break;
 	default:
 		r = -EINVAL;
 		goto out;
-- 
2.34.1