linux-kernel - [RFCv2 12/16] KVM: x86: Enabled protected memory extension

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Date:   Tue, 20 Oct 2020 09:18:55 +0300
From:   "Kirill A. Shutemov" <kirill@...temov.name>
To:     Dave Hansen <dave.hansen@...ux.intel.com>,
        Andy Lutomirski <luto@...nel.org>,
        Peter Zijlstra <peterz@...radead.org>,
        Paolo Bonzini <pbonzini@...hat.com>,
        Sean Christopherson <sean.j.christopherson@...el.com>,
        Vitaly Kuznetsov <vkuznets@...hat.com>,
        Wanpeng Li <wanpengli@...cent.com>,
        Jim Mattson <jmattson@...gle.com>,
        Joerg Roedel <joro@...tes.org>
Cc:     David Rientjes <rientjes@...gle.com>,
        Andrea Arcangeli <aarcange@...hat.com>,
        Kees Cook <keescook@...omium.org>,
        Will Drewry <wad@...omium.org>,
        "Edgecombe, Rick P" <rick.p.edgecombe@...el.com>,
        "Kleen, Andi" <andi.kleen@...el.com>,
        Liran Alon <liran.alon@...cle.com>,
        Mike Rapoport <rppt@...nel.org>, x86@...nel.org,
        kvm@...r.kernel.org, linux-mm@...ck.org,
        linux-kernel@...r.kernel.org,
        "Kirill A. Shutemov" <kirill.shutemov@...ux.intel.com>
Subject: [RFCv2 12/16] KVM: x86: Enabled protected memory extension

Wire up hypercalls for the feature and define VM_KVM_PROTECTED.

Signed-off-by: Kirill A. Shutemov <kirill.shutemov@...ux.intel.com>
---
 arch/x86/Kconfig     | 1 +
 arch/x86/kvm/Kconfig | 1 +
 arch/x86/kvm/cpuid.c | 3 ++-
 arch/x86/kvm/x86.c   | 9 +++++++++
 include/linux/mm.h   | 6 ++++++
 5 files changed, 19 insertions(+), 1 deletion(-)

diff --git a/arch/x86/Kconfig b/arch/x86/Kconfig
index b22b95517437..0bcbdadb97d6 100644
--- a/arch/x86/Kconfig
+++ b/arch/x86/Kconfig
@@ -807,6 +807,7 @@ config KVM_GUEST
 	select X86_HV_CALLBACK_VECTOR
 	select X86_MEM_ENCRYPT_COMMON
 	select SWIOTLB
+	select ARCH_USES_HIGH_VMA_FLAGS
 	default y
 	help
 	  This option enables various optimizations for running under the KVM
diff --git a/arch/x86/kvm/Kconfig b/arch/x86/kvm/Kconfig
index fbd5bd7a945a..2ea77c2a8029 100644
--- a/arch/x86/kvm/Kconfig
+++ b/arch/x86/kvm/Kconfig
@@ -46,6 +46,7 @@ config KVM
 	select KVM_GENERIC_DIRTYLOG_READ_PROTECT
 	select KVM_VFIO
 	select SRCU
+	select HAVE_KVM_PROTECTED_MEMORY
 	help
 	  Support hosting fully virtualized guest machines using hardware
 	  virtualization extensions.  You will need a fairly recent
diff --git a/arch/x86/kvm/cpuid.c b/arch/x86/kvm/cpuid.c
index 3fd6eec202d7..eed33db032fb 100644
--- a/arch/x86/kvm/cpuid.c
+++ b/arch/x86/kvm/cpuid.c
@@ -746,7 +746,8 @@ static inline int __do_cpuid_func(struct kvm_cpuid_array *array, u32 function)
 			     (1 << KVM_FEATURE_PV_SEND_IPI) |
 			     (1 << KVM_FEATURE_POLL_CONTROL) |
 			     (1 << KVM_FEATURE_PV_SCHED_YIELD) |
-			     (1 << KVM_FEATURE_ASYNC_PF_INT);
+			     (1 << KVM_FEATURE_ASYNC_PF_INT) |
+			     (1 << KVM_FEATURE_MEM_PROTECTED);
 
 		if (sched_info_on())
 			entry->eax |= (1 << KVM_FEATURE_STEAL_TIME);
diff --git a/arch/x86/kvm/x86.c b/arch/x86/kvm/x86.c
index ce856e0ece84..e89ff39204f0 100644
--- a/arch/x86/kvm/x86.c
+++ b/arch/x86/kvm/x86.c
@@ -7752,6 +7752,15 @@ int kvm_emulate_hypercall(struct kvm_vcpu *vcpu)
 		kvm_sched_yield(vcpu->kvm, a0);
 		ret = 0;
 		break;
+	case KVM_HC_ENABLE_MEM_PROTECTED:
+		ret = kvm_protect_all_memory(vcpu->kvm);
+		break;
+	case KVM_HC_MEM_SHARE:
+		ret = kvm_protect_memory(vcpu->kvm, a0, a1, false);
+		break;
+	case KVM_HC_MEM_UNSHARE:
+		ret = kvm_protect_memory(vcpu->kvm, a0, a1, true);
+		break;
 	default:
 		ret = -KVM_ENOSYS;
 		break;
diff --git a/include/linux/mm.h b/include/linux/mm.h
index c8d8cdcbc425..ee274d27e764 100644
--- a/include/linux/mm.h
+++ b/include/linux/mm.h
@@ -304,11 +304,13 @@ extern unsigned int kobjsize(const void *objp);
 #define VM_HIGH_ARCH_BIT_2	34	/* bit only usable on 64-bit architectures */
 #define VM_HIGH_ARCH_BIT_3	35	/* bit only usable on 64-bit architectures */
 #define VM_HIGH_ARCH_BIT_4	36	/* bit only usable on 64-bit architectures */
+#define VM_HIGH_ARCH_BIT_5	37	/* bit only usable on 64-bit architectures */
 #define VM_HIGH_ARCH_0	BIT(VM_HIGH_ARCH_BIT_0)
 #define VM_HIGH_ARCH_1	BIT(VM_HIGH_ARCH_BIT_1)
 #define VM_HIGH_ARCH_2	BIT(VM_HIGH_ARCH_BIT_2)
 #define VM_HIGH_ARCH_3	BIT(VM_HIGH_ARCH_BIT_3)
 #define VM_HIGH_ARCH_4	BIT(VM_HIGH_ARCH_BIT_4)
+#define VM_HIGH_ARCH_5	BIT(VM_HIGH_ARCH_BIT_5)
 #endif /* CONFIG_ARCH_USES_HIGH_VMA_FLAGS */
 
 #ifdef CONFIG_ARCH_HAS_PKEYS
@@ -342,7 +344,11 @@ extern unsigned int kobjsize(const void *objp);
 # define VM_MAPPED_COPY	VM_ARCH_1	/* T if mapped copy of data (nommu mmap) */
 #endif
 
+#if defined(CONFIG_X86_64) && defined(CONFIG_KVM)
+#define VM_KVM_PROTECTED VM_HIGH_ARCH_5
+#else
 #define VM_KVM_PROTECTED 0
+#endif
 
 #ifndef VM_GROWSUP
 # define VM_GROWSUP	VM_NONE
-- 
2.26.2