From: Xiaoyao Li <xiaoyao.li@intel.com>
To: Paolo Bonzini <pbonzini@redhat.com>,
Sean Christopherson <seanjc@google.com>,
Vitaly Kuznetsov <vkuznets@redhat.com>,
Wanpeng Li <wanpengli@tencent.com>,
Jim Mattson <jmattson@google.com>, Joerg Roedel <joro@8bytes.org>
Cc: xiaoyao.li@intel.com, erdemaktas@google.com,
Connor Kuehl <ckuehl@redhat.com>,
x86@kernel.org, linux-kernel@vger.kernel.org,
kvm@vger.kernel.org, isaku.yamahata@intel.com,
Kai Huang <kai.huang@intel.com>
Subject: [PATCH 10/11] KVM: Disallow read-only memory for x86 TDX
Date: Fri, 12 Nov 2021 23:37:32 +0800 [thread overview]
Message-ID: <20211112153733.2767561-11-xiaoyao.li@intel.com> (raw)
In-Reply-To: <20211112153733.2767561-1-xiaoyao.li@intel.com>
From: Isaku Yamahata <isaku.yamahata@intel.com>
TDX doesn't expose permission bits to the VMM in the SEPT tables, i.e.,
doesn't support read-only private memory.
Introduce kvm_arch_support_readonly_mem(), which returns true except for
x86. x86 has its own implementation based on vm_type that returns faluse
for TDX VM.
Propagate it to KVM_CAP_READONLY_MEM to allow reporting on a per-VM
basis.
Co-developed-by: Sean Christopherson <sean.j.christopherson@intel.com>
Signed-off-by: Sean Christopherson <sean.j.christopherson@intel.com>
Signed-off-by: Isaku Yamahata <isaku.yamahata@intel.com>
Signed-off-by: Xiaoyao Li <xiaoyao.li@intel.com>
---
arch/x86/kvm/x86.c | 9 ++++++++-
include/linux/kvm_host.h | 1 +
virt/kvm/kvm_main.c | 19 ++++++++++++++-----
3 files changed, 23 insertions(+), 6 deletions(-)
diff --git a/arch/x86/kvm/x86.c b/arch/x86/kvm/x86.c
index d06ee07bd486..f091a4d3c8f2 100644
--- a/arch/x86/kvm/x86.c
+++ b/arch/x86/kvm/x86.c
@@ -4079,7 +4079,6 @@ int kvm_vm_ioctl_check_extension(struct kvm *kvm, long ext)
case KVM_CAP_ASYNC_PF_INT:
case KVM_CAP_GET_TSC_KHZ:
case KVM_CAP_KVMCLOCK_CTRL:
- case KVM_CAP_READONLY_MEM:
case KVM_CAP_HYPERV_TIME:
case KVM_CAP_IOAPIC_POLARITY_IGNORED:
case KVM_CAP_TSC_DEADLINE_TIMER:
@@ -4202,6 +4201,9 @@ int kvm_vm_ioctl_check_extension(struct kvm *kvm, long ext)
if (static_call(kvm_x86_is_vm_type_supported)(KVM_X86_TDX_VM))
r |= BIT(KVM_X86_TDX_VM);
break;
+ case KVM_CAP_READONLY_MEM:
+ r = kvm && !kvm_arch_support_readonly_mem(kvm) ? 0 : 1;
+ break;
default:
break;
}
@@ -12609,6 +12611,11 @@ int kvm_sev_es_string_io(struct kvm_vcpu *vcpu, unsigned int size,
}
EXPORT_SYMBOL_GPL(kvm_sev_es_string_io);
+bool kvm_arch_support_readonly_mem(struct kvm *kvm)
+{
+ return kvm->arch.vm_type != KVM_X86_TDX_VM;
+}
+
EXPORT_TRACEPOINT_SYMBOL_GPL(kvm_entry);
EXPORT_TRACEPOINT_SYMBOL_GPL(kvm_exit);
EXPORT_TRACEPOINT_SYMBOL_GPL(kvm_fast_mmio);
diff --git a/include/linux/kvm_host.h b/include/linux/kvm_host.h
index 60a35d9fe259..1dbabf199c13 100644
--- a/include/linux/kvm_host.h
+++ b/include/linux/kvm_host.h
@@ -1071,6 +1071,7 @@ bool kvm_arch_dy_has_pending_interrupt(struct kvm_vcpu *vcpu);
int kvm_arch_post_init_vm(struct kvm *kvm);
void kvm_arch_pre_destroy_vm(struct kvm *kvm);
int kvm_arch_create_vm_debugfs(struct kvm *kvm);
+bool kvm_arch_support_readonly_mem(struct kvm *kvm);
#ifndef __KVM_HAVE_ARCH_VM_ALLOC
/*
diff --git a/virt/kvm/kvm_main.c b/virt/kvm/kvm_main.c
index 3f6d450355f0..c288c92a9c82 100644
--- a/virt/kvm/kvm_main.c
+++ b/virt/kvm/kvm_main.c
@@ -1421,13 +1421,22 @@ static void update_memslots(struct kvm_memslots *slots,
}
}
-static int check_memory_region_flags(const struct kvm_userspace_memory_region *mem)
+bool __weak kvm_arch_support_readonly_mem(struct kvm *kvm)
{
- u32 valid_flags = KVM_MEM_LOG_DIRTY_PAGES;
-
#ifdef __KVM_HAVE_READONLY_MEM
- valid_flags |= KVM_MEM_READONLY;
+ return true;
+#else
+ return false;
#endif
+}
+
+static int check_memory_region_flags(struct kvm *kvm,
+ const struct kvm_userspace_memory_region *mem)
+{
+ u32 valid_flags = KVM_MEM_LOG_DIRTY_PAGES;
+
+ if (kvm_arch_support_readonly_mem(kvm))
+ valid_flags |= KVM_MEM_READONLY;
if (mem->flags & ~valid_flags)
return -EINVAL;
@@ -1664,7 +1673,7 @@ int __kvm_set_memory_region(struct kvm *kvm,
int as_id, id;
int r;
- r = check_memory_region_flags(mem);
+ r = check_memory_region_flags(kvm, mem);
if (r)
return r;
--
2.27.0
next prev parent reply other threads:[~2021-11-12 15:39 UTC|newest]
Thread overview: 22+ messages / expand[flat|nested] mbox.gz Atom feed top
2021-11-12 15:37 [PATCH 00/11] KVM: x86: TDX preparation of introducing vm_type and blocking ioctls based on vm_type Xiaoyao Li
2021-11-12 15:37 ` [PATCH 01/11] KVM: x86: Introduce vm_type to differentiate normal VMs from confidential VMs Xiaoyao Li
2021-11-12 16:47 ` Sean Christopherson
2021-11-15 15:37 ` Xiaoyao Li
2021-11-12 15:37 ` [PATCH 02/11] KVM: x86: Disable direct IRQ injection for TDX Xiaoyao Li
2021-11-12 15:37 ` [PATCH 03/11] KVM: x86: Clean up kvm_vcpu_ioctl_x86_setup_mce() Xiaoyao Li
2021-12-02 1:19 ` Xiaoyao Li
2021-11-12 15:37 ` [PATCH 04/11] KVM: x86: Disable MCE related stuff for TDX Xiaoyao Li
2021-11-12 17:01 ` Sean Christopherson
2021-11-15 15:39 ` Xiaoyao Li
2021-11-12 15:37 ` [PATCH 05/11] KVM: x86: Disallow tsc manipulation " Xiaoyao Li
2021-11-12 15:37 ` [PATCH 06/11] KVM: x86: Disable in-kernel I/O APIC and level routes " Xiaoyao Li
2021-11-12 15:37 ` [PATCH 07/11] KVM: x86: Disable SMM " Xiaoyao Li
2021-11-12 18:04 ` Sean Christopherson
2021-11-12 18:35 ` Sean Christopherson
2021-12-01 6:29 ` Xiaoyao Li
2021-11-12 15:37 ` [PATCH 08/11] KVM: x86: Disable INIT/SIPI " Xiaoyao Li
2021-11-12 15:37 ` [PATCH 09/11] KVM: x86: Block ioctls to access guest state " Xiaoyao Li
2021-11-12 15:37 ` Xiaoyao Li [this message]
2021-11-12 16:52 ` [PATCH 10/11] KVM: Disallow read-only memory for x86 TDX Sean Christopherson
2021-11-14 3:43 ` Xiaoyao Li
2021-11-12 15:37 ` [PATCH 11/11] KVM: Disallow dirty logging " Xiaoyao Li
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