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From: Sean Christopherson <sean.j.christopherson@intel.com>
To: Paolo Bonzini <pbonzini@redhat.com>
Cc: "Paul Mackerras" <paulus@ozlabs.org>,
	"Christian Borntraeger" <borntraeger@de.ibm.com>,
	"Janosch Frank" <frankja@linux.ibm.com>,
	"David Hildenbrand" <david@redhat.com>,
	"Cornelia Huck" <cohuck@redhat.com>,
	"Sean Christopherson" <sean.j.christopherson@intel.com>,
	"Vitaly Kuznetsov" <vkuznets@redhat.com>,
	"Wanpeng Li" <wanpengli@tencent.com>,
	"Jim Mattson" <jmattson@google.com>,
	"Joerg Roedel" <joro@8bytes.org>, "Marc Zyngier" <maz@kernel.org>,
	"James Morse" <james.morse@arm.com>,
	"Julien Thierry" <julien.thierry.kdev@gmail.com>,
	"Suzuki K Poulose" <suzuki.poulose@arm.com>,
	linux-mips@vger.kernel.org, kvm@vger.kernel.org,
	kvm-ppc@vger.kernel.org, linux-arm-kernel@lists.infradead.org,
	kvmarm@lists.cs.columbia.edu, linux-kernel@vger.kernel.org,
	"Christoffer Dall" <christoffer.dall@arm.com>,
	"Peter Xu" <peterx@redhat.com>,
	"Philippe Mathieu-Daudé" <f4bug@amsat.org>
Subject: [PATCH v5 08/19] KVM: Refactor error handling for setting memory region
Date: Tue, 21 Jan 2020 14:31:46 -0800
Message-ID: <20200121223157.15263-9-sean.j.christopherson@intel.com> (raw)
In-Reply-To: <20200121223157.15263-1-sean.j.christopherson@intel.com>

Replace a big pile o' gotos with returns to make it more obvious what
error code is being returned, and to prepare for refactoring the
functional, i.e. post-checks, portion of __kvm_set_memory_region().

Reviewed-by: Janosch Frank <frankja@linux.ibm.com>
Reviewed-by: Philippe Mathieu-Daudé <f4bug@amsat.org>
Signed-off-by: Sean Christopherson <sean.j.christopherson@intel.com>
---
 virt/kvm/kvm_main.c | 40 ++++++++++++++++++----------------------
 1 file changed, 18 insertions(+), 22 deletions(-)

diff --git a/virt/kvm/kvm_main.c b/virt/kvm/kvm_main.c
index 9bc51f062022..fdf045a5d240 100644
--- a/virt/kvm/kvm_main.c
+++ b/virt/kvm/kvm_main.c
@@ -1004,34 +1004,33 @@ int __kvm_set_memory_region(struct kvm *kvm,
 
 	r = check_memory_region_flags(mem);
 	if (r)
-		goto out;
+		return r;
 
-	r = -EINVAL;
 	as_id = mem->slot >> 16;
 	id = (u16)mem->slot;
 
 	/* General sanity checks */
 	if (mem->memory_size & (PAGE_SIZE - 1))
-		goto out;
+		return -EINVAL;
 	if (mem->guest_phys_addr & (PAGE_SIZE - 1))
-		goto out;
+		return -EINVAL;
 	/* We can read the guest memory with __xxx_user() later on. */
 	if ((id < KVM_USER_MEM_SLOTS) &&
 	    ((mem->userspace_addr & (PAGE_SIZE - 1)) ||
 	     !access_ok((void __user *)(unsigned long)mem->userspace_addr,
 			mem->memory_size)))
-		goto out;
+		return -EINVAL;
 	if (as_id >= KVM_ADDRESS_SPACE_NUM || id >= KVM_MEM_SLOTS_NUM)
-		goto out;
+		return -EINVAL;
 	if (mem->guest_phys_addr + mem->memory_size < mem->guest_phys_addr)
-		goto out;
+		return -EINVAL;
 
 	slot = id_to_memslot(__kvm_memslots(kvm, as_id), id);
 	base_gfn = mem->guest_phys_addr >> PAGE_SHIFT;
 	npages = mem->memory_size >> PAGE_SHIFT;
 
 	if (npages > KVM_MEM_MAX_NR_PAGES)
-		goto out;
+		return -EINVAL;
 
 	new = old = *slot;
 
@@ -1048,20 +1047,18 @@ int __kvm_set_memory_region(struct kvm *kvm,
 			if ((new.userspace_addr != old.userspace_addr) ||
 			    (npages != old.npages) ||
 			    ((new.flags ^ old.flags) & KVM_MEM_READONLY))
-				goto out;
+				return -EINVAL;
 
 			if (base_gfn != old.base_gfn)
 				change = KVM_MR_MOVE;
 			else if (new.flags != old.flags)
 				change = KVM_MR_FLAGS_ONLY;
-			else { /* Nothing to change. */
-				r = 0;
-				goto out;
-			}
+			else /* Nothing to change. */
+				return 0;
 		}
 	} else {
 		if (!old.npages)
-			goto out;
+			return -EINVAL;
 
 		change = KVM_MR_DELETE;
 		new.base_gfn = 0;
@@ -1070,29 +1067,29 @@ int __kvm_set_memory_region(struct kvm *kvm,
 
 	if ((change == KVM_MR_CREATE) || (change == KVM_MR_MOVE)) {
 		/* Check for overlaps */
-		r = -EEXIST;
 		kvm_for_each_memslot(slot, __kvm_memslots(kvm, as_id)) {
 			if (slot->id == id)
 				continue;
 			if (!((base_gfn + npages <= slot->base_gfn) ||
 			      (base_gfn >= slot->base_gfn + slot->npages)))
-				goto out;
+				return -EEXIST;
 		}
 	}
 
-	r = -ENOMEM;
-
 	/* Allocate/free page dirty bitmap as needed */
 	if (!(new.flags & KVM_MEM_LOG_DIRTY_PAGES))
 		new.dirty_bitmap = NULL;
 	else if (!new.dirty_bitmap) {
-		if (kvm_create_dirty_bitmap(&new) < 0)
-			goto out;
+		r = kvm_create_dirty_bitmap(&new);
+		if (r)
+			return r;
 	}
 
 	slots = kvzalloc(sizeof(struct kvm_memslots), GFP_KERNEL_ACCOUNT);
-	if (!slots)
+	if (!slots) {
+		r = -ENOMEM;
 		goto out_bitmap;
+	}
 	memcpy(slots, __kvm_memslots(kvm, as_id), sizeof(struct kvm_memslots));
 
 	if ((change == KVM_MR_DELETE) || (change == KVM_MR_MOVE)) {
@@ -1143,7 +1140,6 @@ int __kvm_set_memory_region(struct kvm *kvm,
 out_bitmap:
 	if (new.dirty_bitmap && !old.dirty_bitmap)
 		kvm_destroy_dirty_bitmap(&new);
-out:
 	return r;
 }
 EXPORT_SYMBOL_GPL(__kvm_set_memory_region);
-- 
2.24.1


  parent reply index

Thread overview: 70+ messages / expand[flat|nested]  mbox.gz  Atom feed  top
2020-01-21 22:31 [PATCH v5 00/19] KVM: Dynamically size memslot arrays Sean Christopherson
2020-01-21 22:31 ` [PATCH v5 01/19] KVM: x86: Allocate new rmap and large page tracking when moving memslot Sean Christopherson
2020-02-05 21:49   ` Peter Xu
2020-02-05 23:55     ` Sean Christopherson
2020-02-06  2:00       ` Peter Xu
2020-02-06  2:17         ` Sean Christopherson
2020-02-06  2:58           ` Peter Xu
2020-02-06  5:05             ` Sean Christopherson
2020-01-21 22:31 ` [PATCH v5 02/19] KVM: Reinstall old memslots if arch preparation fails Sean Christopherson
2020-02-05 22:08   ` Peter Xu
2020-01-21 22:31 ` [PATCH v5 03/19] KVM: Don't free new memslot if allocation of said memslot fails Sean Christopherson
2020-02-05 22:28   ` Peter Xu
2020-01-21 22:31 ` [PATCH v5 04/19] KVM: PPC: Move memslot memory allocation into prepare_memory_region() Sean Christopherson
2020-02-05 22:41   ` Peter Xu
2020-01-21 22:31 ` [PATCH v5 05/19] KVM: x86: Allocate memslot resources during prepare_memory_region() Sean Christopherson
2020-01-21 22:31 ` [PATCH v5 06/19] KVM: Drop kvm_arch_create_memslot() Sean Christopherson
2020-02-05 22:45   ` Peter Xu
2020-01-21 22:31 ` [PATCH v5 07/19] KVM: Explicitly free allocated-but-unused dirty bitmap Sean Christopherson
2020-01-21 22:31 ` Sean Christopherson [this message]
2020-02-05 22:48   ` [PATCH v5 08/19] KVM: Refactor error handling for setting memory region Peter Xu
2020-01-21 22:31 ` [PATCH v5 09/19] KVM: Move setting of memslot into helper routine Sean Christopherson
2020-02-06 16:26   ` Peter Xu
2020-01-21 22:31 ` [PATCH v5 10/19] KVM: Drop "const" attribute from old memslot in commit_memory_region() Sean Christopherson
2020-02-06 16:26   ` Peter Xu
2020-01-21 22:31 ` [PATCH v5 11/19] KVM: x86: Free arrays for old memslot when moving memslot's base gfn Sean Christopherson
2020-01-21 22:31 ` [PATCH v5 12/19] KVM: Move memslot deletion to helper function Sean Christopherson
2020-02-06 16:14   ` Peter Xu
2020-02-06 16:28     ` Sean Christopherson
2020-02-06 16:51       ` Peter Xu
2020-02-07 17:59         ` Sean Christopherson
2020-02-07 18:07           ` Sean Christopherson
2020-02-07 18:17           ` Peter Xu
2020-01-21 22:31 ` [PATCH v5 13/19] KVM: Simplify kvm_free_memslot() and all its descendents Sean Christopherson
2020-02-06 16:29   ` Peter Xu
2020-01-21 22:31 ` [PATCH v5 14/19] KVM: Clean up local variable usage in __kvm_set_memory_region() Sean Christopherson
2020-02-06 19:06   ` Peter Xu
2020-02-06 19:22     ` Sean Christopherson
2020-02-06 19:36       ` Peter Xu
2020-01-21 22:31 ` [PATCH v5 15/19] KVM: Provide common implementation for generic dirty log functions Sean Christopherson
2020-02-06 20:02   ` Peter Xu
2020-02-06 21:21     ` Sean Christopherson
2020-02-06 21:41       ` Peter Xu
2020-02-07 19:45         ` Sean Christopherson
2020-02-08  0:18           ` Peter Xu
2020-02-08  0:42             ` Sean Christopherson
2020-02-08  0:53               ` Peter Xu
2020-02-08  1:29                 ` Sean Christopherson
2020-02-17 15:39                   ` Vitaly Kuznetsov
2020-02-18 17:10                     ` Sean Christopherson
2020-02-17 15:35           ` Vitaly Kuznetsov
2020-02-06 21:24   ` Peter Xu
2020-01-21 22:31 ` [PATCH v5 16/19] KVM: Ensure validity of memslot with respect to kvm_get_dirty_log() Sean Christopherson
2020-01-21 22:31 ` [PATCH v5 17/19] KVM: Terminate memslot walks via used_slots Sean Christopherson
2020-02-06 21:09   ` Peter Xu
2020-02-07 18:33     ` Sean Christopherson
2020-02-07 20:39       ` Peter Xu
2020-02-07 21:10         ` Sean Christopherson
2020-02-07 21:46           ` Peter Xu
2020-02-07 22:03             ` Sean Christopherson
2020-02-07 22:24               ` Peter Xu
2020-01-21 22:31 ` [PATCH v5 18/19] KVM: Dynamically size memslot array based on number of used slots Sean Christopherson
2020-02-06 22:12   ` Peter Xu
2020-02-07 15:38     ` Sean Christopherson
2020-02-07 16:05       ` Peter Xu
2020-02-07 16:15         ` Sean Christopherson
2020-02-07 16:37           ` Peter Xu
2020-02-07 16:47             ` Sean Christopherson
2020-01-21 22:31 ` [PATCH v5 19/19] KVM: selftests: Add test for KVM_SET_USER_MEMORY_REGION Sean Christopherson
2020-02-06 22:30   ` Peter Xu
2020-02-06 23:11     ` Sean Christopherson

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