linux-kernel - [PATCH v3 08/21] KVM: X86: Drop x86_set_memory

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Date:   Thu,  9 Jan 2020 09:57:16 -0500
From:   Peter Xu <peterx@...hat.com>
To:     kvm@...r.kernel.org, linux-kernel@...r.kernel.org
Cc:     Christophe de Dinechin <dinechin@...hat.com>,
        "Michael S . Tsirkin" <mst@...hat.com>,
        Paolo Bonzini <pbonzini@...hat.com>,
        Sean Christopherson <sean.j.christopherson@...el.com>,
        Yan Zhao <yan.y.zhao@...el.com>,
        Alex Williamson <alex.williamson@...hat.com>,
        Jason Wang <jasowang@...hat.com>,
        Kevin Kevin <kevin.tian@...el.com>,
        Vitaly Kuznetsov <vkuznets@...hat.com>, peterx@...hat.com,
        "Dr . David Alan Gilbert" <dgilbert@...hat.com>
Subject: [PATCH v3 08/21] KVM: X86: Drop x86_set_memory_region()

The helper x86_set_memory_region() is only used in vmx_set_tss_addr()
and kvm_arch_destroy_vm().  Push the lock upper in both cases.  With
that, drop x86_set_memory_region().

This prepares to allow __x86_set_memory_region() to return a HVA
mapped, because the HVA will need to be protected by the lock too even
after __x86_set_memory_region() returns.

Signed-off-by: Peter Xu <peterx@...hat.com>
---
 arch/x86/include/asm/kvm_host.h |  1 -
 arch/x86/kvm/vmx/vmx.c          |  7 +++++--
 arch/x86/kvm/x86.c              | 22 +++++++---------------
 3 files changed, 12 insertions(+), 18 deletions(-)

diff --git a/arch/x86/include/asm/kvm_host.h b/arch/x86/include/asm/kvm_host.h
index 159a28512e4c..eb6673c7d2e3 100644
--- a/arch/x86/include/asm/kvm_host.h
+++ b/arch/x86/include/asm/kvm_host.h
@@ -1619,7 +1619,6 @@ void __kvm_request_immediate_exit(struct kvm_vcpu *vcpu);
 int kvm_is_in_guest(void);
 
 int __x86_set_memory_region(struct kvm *kvm, int id, gpa_t gpa, u32 size);
-int x86_set_memory_region(struct kvm *kvm, int id, gpa_t gpa, u32 size);
 bool kvm_vcpu_is_reset_bsp(struct kvm_vcpu *vcpu);
 bool kvm_vcpu_is_bsp(struct kvm_vcpu *vcpu);
 
diff --git a/arch/x86/kvm/vmx/vmx.c b/arch/x86/kvm/vmx/vmx.c
index 7add2fc8d8e9..7e3d370209e0 100644
--- a/arch/x86/kvm/vmx/vmx.c
+++ b/arch/x86/kvm/vmx/vmx.c
@@ -4482,8 +4482,11 @@ static int vmx_set_tss_addr(struct kvm *kvm, unsigned int addr)
 	if (enable_unrestricted_guest)
 		return 0;
 
-	ret = x86_set_memory_region(kvm, TSS_PRIVATE_MEMSLOT, addr,
-				    PAGE_SIZE * 3);
+	mutex_lock(&kvm->slots_lock);
+	ret = __x86_set_memory_region(kvm, TSS_PRIVATE_MEMSLOT, addr,
+				      PAGE_SIZE * 3);
+	mutex_unlock(&kvm->slots_lock);
+
 	if (ret)
 		return ret;
 	to_kvm_vmx(kvm)->tss_addr = addr;
diff --git a/arch/x86/kvm/x86.c b/arch/x86/kvm/x86.c
index 93bbbce67a03..c4d3972dcd14 100644
--- a/arch/x86/kvm/x86.c
+++ b/arch/x86/kvm/x86.c
@@ -9636,18 +9636,6 @@ int __x86_set_memory_region(struct kvm *kvm, int id, gpa_t gpa, u32 size)
 }
 EXPORT_SYMBOL_GPL(__x86_set_memory_region);
 
-int x86_set_memory_region(struct kvm *kvm, int id, gpa_t gpa, u32 size)
-{
-	int r;
-
-	mutex_lock(&kvm->slots_lock);
-	r = __x86_set_memory_region(kvm, id, gpa, size);
-	mutex_unlock(&kvm->slots_lock);
-
-	return r;
-}
-EXPORT_SYMBOL_GPL(x86_set_memory_region);
-
 void kvm_arch_pre_destroy_vm(struct kvm *kvm)
 {
 	kvm_mmu_pre_destroy_vm(kvm);
@@ -9661,9 +9649,13 @@ void kvm_arch_destroy_vm(struct kvm *kvm)
 		 * unless the the memory map has changed due to process exit
 		 * or fd copying.
 		 */
-		x86_set_memory_region(kvm, APIC_ACCESS_PAGE_PRIVATE_MEMSLOT, 0, 0);
-		x86_set_memory_region(kvm, IDENTITY_PAGETABLE_PRIVATE_MEMSLOT, 0, 0);
-		x86_set_memory_region(kvm, TSS_PRIVATE_MEMSLOT, 0, 0);
+		mutex_lock(&kvm->slots_lock);
+		__x86_set_memory_region(kvm, APIC_ACCESS_PAGE_PRIVATE_MEMSLOT,
+					0, 0);
+		__x86_set_memory_region(kvm, IDENTITY_PAGETABLE_PRIVATE_MEMSLOT,
+					0, 0);
+		__x86_set_memory_region(kvm, TSS_PRIVATE_MEMSLOT, 0, 0);
+		mutex_unlock(&kvm->slots_lock);
 	}
 	if (kvm_x86_ops->vm_destroy)
 		kvm_x86_ops->vm_destroy(kvm);
-- 
2.24.1