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From: Ben Gardon <bgardon@google.com>
To: linux-kernel@vger.kernel.org, kvm@vger.kernel.org,
	linux-kselftest@vger.kernel.org
Cc: Paolo Bonzini <pbonzini@redhat.com>,
	Cannon Matthews <cannonmatthews@google.com>,
	Peter Xu <peterx@redhat.com>, Andrew Jones <drjones@redhat.com>,
	Peter Shier <pshier@google.com>, Oliver Upton <oupton@google.com>,
	Ben Gardon <bgardon@google.com>
Subject: [PATCH v4 10/10] KVM: selftests: Move memslot 0 above KVM internal memslots
Date: Thu, 23 Jan 2020 10:04:36 -0800
Message-ID: <20200123180436.99487-11-bgardon@google.com> (raw)
In-Reply-To: <20200123180436.99487-1-bgardon@google.com>

KVM creates internal memslots between 3 and 4 GiB paddrs on the first
vCPU creation. If memslot 0 is large enough it collides with these
memslots an causes vCPU creation to fail. Instead of creating memslot 0
at paddr 0, start it 4G into the guest physical address space.

Signed-off-by: Ben Gardon <bgardon@google.com>
---
 tools/testing/selftests/kvm/lib/kvm_util.c | 11 +++++++----
 1 file changed, 7 insertions(+), 4 deletions(-)

diff --git a/tools/testing/selftests/kvm/lib/kvm_util.c b/tools/testing/selftests/kvm/lib/kvm_util.c
index 5b971c04f1643..427c88d32e988 100644
--- a/tools/testing/selftests/kvm/lib/kvm_util.c
+++ b/tools/testing/selftests/kvm/lib/kvm_util.c
@@ -130,9 +130,11 @@ _Static_assert(sizeof(vm_guest_mode_string)/sizeof(char *) == NUM_VM_MODES,
  *
  * Creates a VM with the mode specified by mode (e.g. VM_MODE_P52V48_4K).
  * When phy_pages is non-zero, a memory region of phy_pages physical pages
- * is created and mapped starting at guest physical address 0.  The file
- * descriptor to control the created VM is created with the permissions
- * given by perm (e.g. O_RDWR).
+ * is created, starting at 4G into the guest physical address space to avoid
+ * KVM internal memslots which map the region between 3G and 4G. If tests need
+ * to use the physical region between 0 and 3G, they can allocate another
+ * memslot for that region. The file descriptor to control the created VM is
+ * created with the permissions given by perm (e.g. O_RDWR).
  */
 struct kvm_vm *_vm_create(enum vm_guest_mode mode, uint64_t phy_pages, int perm)
 {
@@ -231,7 +233,8 @@ struct kvm_vm *_vm_create(enum vm_guest_mode mode, uint64_t phy_pages, int perm)
 	vm->vpages_mapped = sparsebit_alloc();
 	if (phy_pages != 0)
 		vm_userspace_mem_region_add(vm, VM_MEM_SRC_ANONYMOUS,
-					    0, 0, phy_pages, 0);
+					    KVM_INTERNAL_MEMSLOTS_END_PADDR,
+					    0, phy_pages, 0);
 
 	return vm;
 }
-- 
2.25.0.341.g760bfbb309-goog


  parent reply index

Thread overview: 35+ messages / expand[flat|nested]  mbox.gz  Atom feed  top
2020-01-23 18:04 [PATCH v4 00/10] Create a userfaultfd demand paging test Ben Gardon
2020-01-23 18:04 ` [PATCH v4 01/10] KVM: selftests: Create a " Ben Gardon
2020-01-24  9:49   ` Andrew Jones
2020-01-27  9:18   ` Thomas Huth
2020-01-23 18:04 ` [PATCH v4 02/10] KVM: selftests: Add demand paging content to the " Ben Gardon
2020-01-23 18:04 ` [PATCH v4 03/10] KVM: selftests: Add configurable demand paging delay Ben Gardon
2020-01-23 18:04 ` [PATCH v4 04/10] KVM: selftests: Add memory size parameter to the demand paging test Ben Gardon
2020-01-24 10:01   ` Andrew Jones
2020-01-23 18:04 ` [PATCH v4 05/10] KVM: selftests: Pass args to vCPU in global vCPU args struct Ben Gardon
2020-01-23 18:04 ` [PATCH v4 06/10] KVM: selftests: Add support for vcpu_args_set to aarch64 and s390x Ben Gardon
2020-01-24  9:03   ` Paolo Bonzini
2020-01-24  9:35     ` Andrew Jones
2020-01-24  9:44       ` Paolo Bonzini
2020-01-24 10:45       ` Andrew Jones
2020-01-24 18:33     ` Christian Borntraeger
2020-01-25  9:34   ` Paolo Bonzini
2020-01-27  8:38     ` Andrew Jones
2020-01-27  9:01   ` Thomas Huth
2020-01-23 18:04 ` [PATCH v4 07/10] KVM: selftests: Support multiple vCPUs in demand paging test Ben Gardon
2020-01-24 10:16   ` Andrew Jones
2020-01-24 10:49   ` Andrew Jones
2020-01-25  9:39     ` Paolo Bonzini
2020-01-27  8:39       ` Andrew Jones
2020-01-23 18:04 ` [PATCH v4 08/10] KVM: selftests: Time guest demand paging Ben Gardon
2020-01-24 10:21   ` Andrew Jones
2020-01-23 18:04 ` [PATCH v4 09/10] KVM: selftests: Stop memslot creation in KVM internal memslot region Ben Gardon
2020-01-24  8:58   ` Paolo Bonzini
2020-01-24 18:41     ` Ben Gardon
2020-01-25  9:37       ` Paolo Bonzini
2020-01-27 17:28         ` Ben Gardon
2020-01-23 18:04 ` Ben Gardon [this message]
2020-01-24  9:01   ` [PATCH v4 10/10] KVM: selftests: Move memslot 0 above KVM internal memslots Paolo Bonzini
2020-01-24 18:53     ` Ben Gardon
2020-01-27  9:42   ` Thomas Huth
2020-01-24  9:03 ` [PATCH v4 00/10] Create a userfaultfd demand paging test Paolo Bonzini

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