From: Paolo Bonzini <pbonzini@redhat.com>
To: "Maciej S. Szmigiero" <maciej.szmigiero@oracle.com>
Cc: linux-kernel@vger.kernel.org, kvm@vger.kernel.org
Subject: Re: [PATCH] selftests: kvm: fix overlapping addresses in memslot_perf_test
Date: Sat, 29 May 2021 12:20:16 +0200 [thread overview]
Message-ID: <fc41bfc4-949f-03c5-3b20-2c1563ad7f62@redhat.com> (raw)
In-Reply-To: <285623f6-52e4-7f8d-fab6-0476a00af68b@oracle.com>
On 28/05/21 21:51, Maciej S. Szmigiero wrote:
> On 28.05.2021 21:11, Paolo Bonzini wrote:
>> The memory that is allocated in vm_create is already mapped close to
>> GPA 0, because test_execute passes the requested memory to
>> prepare_vm. This causes overlapping memory regions and the
>> test crashes. For simplicity just move MEM_GPA higher.
>>
>> Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
>
> I am not sure that I understand the issue correctly, is vm_create_default()
> already reserving low GPAs (around 0x10000000) on some arches or run
> environments?
It maps the number of pages you pass in the second argument, see
vm_create.
if (phy_pages != 0)
vm_userspace_mem_region_add(vm, VM_MEM_SRC_ANONYMOUS,
0, 0, phy_pages, 0);
In this case:
data->vm = vm_create_default(VCPU_ID, mempages, guest_code);
called here:
if (!prepare_vm(data, nslots, maxslots, tdata->guest_code,
mem_size, slot_runtime)) {
where mempages is mem_size, which is declared as:
uint64_t mem_size = tdata->mem_size ? : MEM_SIZE_PAGES;
but actually a better fix is just to pass a small fixed value (e.g.
1024) to vm_create_default, since all other regions are added by hand.
Paolo
next prev parent reply other threads:[~2021-05-29 10:20 UTC|newest]
Thread overview: 12+ messages / expand[flat|nested] mbox.gz Atom feed top
2021-05-28 19:11 [PATCH] selftests: kvm: fix overlapping addresses in memslot_perf_test Paolo Bonzini
2021-05-28 19:51 ` Maciej S. Szmigiero
2021-05-29 10:20 ` Paolo Bonzini [this message]
2021-05-29 23:13 ` Maciej S. Szmigiero
2021-06-02 23:07 ` Maciej S. Szmigiero
2021-06-03 5:26 ` Duan, Zhenzhong
2021-06-03 12:37 ` Andrew Jones
2021-06-03 13:05 ` Maciej S. Szmigiero
2021-06-04 3:35 ` Duan, Zhenzhong
2021-06-04 16:49 ` selftests: kvm: allocating extra mem in slot 0 (Was: Re: [PATCH] selftests: kvm: fix overlapping addresses in memslot_perf_test) Maciej S. Szmigiero
2021-06-08 3:20 ` Duan, Zhenzhong
2021-06-03 13:05 ` [PATCH] selftests: kvm: fix overlapping addresses in memslot_perf_test Maciej S. Szmigiero
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