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Wed, 7 Aug 2019 07:54:29 +0000 (UTC) Received: from [10.36.117.156] (ovpn-117-156.ams2.redhat.com [10.36.117.156]) by smtp.corp.redhat.com (Postfix) with ESMTP id CD0AF5C1D4; Wed, 7 Aug 2019 07:54:27 +0000 (UTC) To: Igor Mammedov , qemu-devel@nongnu.org References: <20190806094834.7691-1-imammedo@redhat.com> <20190806094834.7691-2-imammedo@redhat.com> From: David Hildenbrand Openpgp: preference=signencrypt Autocrypt: addr=david@redhat.com; prefer-encrypt=mutual; keydata= xsFNBFXLn5EBEAC+zYvAFJxCBY9Tr1xZgcESmxVNI/0ffzE/ZQOiHJl6mGkmA1R7/uUpiCjJ dBrn+lhhOYjjNefFQou6478faXE6o2AhmebqT4KiQoUQFV4R7y1KMEKoSyy8hQaK1umALTdL QZLQMzNE74ap+GDK0wnacPQFpcG1AE9RMq3aeErY5tujekBS32jfC/7AnH7I0v1v1TbbK3Gp XNeiN4QroO+5qaSr0ID2sz5jtBLRb15RMre27E1ImpaIv2Jw8NJgW0k/D1RyKCwaTsgRdwuK Kx/Y91XuSBdz0uOyU/S8kM1+ag0wvsGlpBVxRR/xw/E8M7TEwuCZQArqqTCmkG6HGcXFT0V9 PXFNNgV5jXMQRwU0O/ztJIQqsE5LsUomE//bLwzj9IVsaQpKDqW6TAPjcdBDPLHvriq7kGjt WhVhdl0qEYB8lkBEU7V2Yb+SYhmhpDrti9Fq1EsmhiHSkxJcGREoMK/63r9WLZYI3+4W2rAc UucZa4OT27U5ZISjNg3Ev0rxU5UH2/pT4wJCfxwocmqaRr6UYmrtZmND89X0KigoFD/XSeVv jwBRNjPAubK9/k5NoRrYqztM9W6sJqrH8+UWZ1Idd/DdmogJh0gNC0+N42Za9yBRURfIdKSb B3JfpUqcWwE7vUaYrHG1nw54pLUoPG6sAA7Mehl3nd4pZUALHwARAQABzSREYXZpZCBIaWxk ZW5icmFuZCA8ZGF2aWRAcmVkaGF0LmNvbT7CwX4EEwECACgFAljj9eoCGwMFCQlmAYAGCwkI BwMCBhUIAgkKCwQWAgMBAh4BAheAAAoJEE3eEPcA/4Na5IIP/3T/FIQMxIfNzZshIq687qgG 8UbspuE/YSUDdv7r5szYTK6KPTlqN8NAcSfheywbuYD9A4ZeSBWD3/NAVUdrCaRP2IvFyELj xoMvfJccbq45BxzgEspg/bVahNbyuBpLBVjVWwRtFCUEXkyazksSv8pdTMAs9IucChvFmmq3 jJ2vlaz9lYt/lxN246fIVceckPMiUveimngvXZw21VOAhfQ+/sofXF8JCFv2mFcBDoa7eYob s0FLpmqFaeNRHAlzMWgSsP80qx5nWWEvRLdKWi533N2vC/EyunN3HcBwVrXH4hxRBMco3jvM m8VKLKao9wKj82qSivUnkPIwsAGNPdFoPbgghCQiBjBe6A75Z2xHFrzo7t1jg7nQfIyNC7ez MZBJ59sqA9EDMEJPlLNIeJmqslXPjmMFnE7Mby/+335WJYDulsRybN+W5rLT5aMvhC6x6POK z55fMNKrMASCzBJum2Fwjf/VnuGRYkhKCqqZ8gJ3OvmR50tInDV2jZ1DQgc3i550T5JDpToh dPBxZocIhzg+MBSRDXcJmHOx/7nQm3iQ6iLuwmXsRC6f5FbFefk9EjuTKcLMvBsEx+2DEx0E UnmJ4hVg7u1PQ+2Oy+Lh/opK/BDiqlQ8Pz2jiXv5xkECvr/3Sv59hlOCZMOaiLTTjtOIU7Tq 7ut6OL64oAq+zsFNBFXLn5EBEADn1959INH2cwYJv0tsxf5MUCghCj/CA/lc/LMthqQ773ga uB9mN+F1rE9cyyXb6jyOGn+GUjMbnq1o121Vm0+neKHUCBtHyseBfDXHA6m4B3mUTWo13nid 0e4AM71r0DS8+KYh6zvweLX/LL5kQS9GQeT+QNroXcC1NzWbitts6TZ+IrPOwT1hfB4WNC+X 2n4AzDqp3+ILiVST2DT4VBc11Gz6jijpC/KI5Al8ZDhRwG47LUiuQmt3yqrmN63V9wzaPhC+ xbwIsNZlLUvuRnmBPkTJwwrFRZvwu5GPHNndBjVpAfaSTOfppyKBTccu2AXJXWAE1Xjh6GOC 8mlFjZwLxWFqdPHR1n2aPVgoiTLk34LR/bXO+e0GpzFXT7enwyvFFFyAS0Nk1q/7EChPcbRb hJqEBpRNZemxmg55zC3GLvgLKd5A09MOM2BrMea+l0FUR+PuTenh2YmnmLRTro6eZ/qYwWkC u8FFIw4pT0OUDMyLgi+GI1aMpVogTZJ70FgV0pUAlpmrzk/bLbRkF3TwgucpyPtcpmQtTkWS gDS50QG9DR/1As3LLLcNkwJBZzBG6PWbvcOyrwMQUF1nl4SSPV0LLH63+BrrHasfJzxKXzqg rW28CTAE2x8qi7e/6M/+XXhrsMYG+uaViM7n2je3qKe7ofum3s4vq7oFCPsOgwARAQABwsFl BBgBAgAPBQJVy5+RAhsMBQkJZgGAAAoJEE3eEPcA/4NagOsP/jPoIBb/iXVbM+fmSHOjEshl KMwEl/m5iLj3iHnHPVLBUWrXPdS7iQijJA/VLxjnFknhaS60hkUNWexDMxVVP/6lbOrs4bDZ NEWDMktAeqJaFtxackPszlcpRVkAs6Msn9tu8hlvB517pyUgvuD7ZS9gGOMmYwFQDyytpepo YApVV00P0u3AaE0Cj/o71STqGJKZxcVhPaZ+LR+UCBZOyKfEyq+ZN311VpOJZ1IvTExf+S/5 lqnciDtbO3I4Wq0ArLX1gs1q1XlXLaVaA3yVqeC8E7kOchDNinD3hJS4OX0e1gdsx/e6COvy qNg5aL5n0Kl4fcVqM0LdIhsubVs4eiNCa5XMSYpXmVi3HAuFyg9dN+x8thSwI836FoMASwOl C7tHsTjnSGufB+D7F7ZBT61BffNBBIm1KdMxcxqLUVXpBQHHlGkbwI+3Ye+nE6HmZH7IwLwV W+Ajl7oYF+jeKaH4DZFtgLYGLtZ1LDwKPjX7VAsa4Yx7S5+EBAaZGxK510MjIx6SGrZWBrrV TEvdV00F2MnQoeXKzD7O4WFbL55hhyGgfWTHwZ457iN9SgYi1JLPqWkZB0JRXIEtjd4JEQcx +8Umfre0Xt4713VxMygW0PnQt5aSQdMD58jHFxTk092mU+yIHj5LeYgvwSgZN4airXk5yRXl SE+xAvmumFBY Organization: Red Hat GmbH Message-ID: Date: Wed, 7 Aug 2019 09:54:27 +0200 User-Agent: Mozilla/5.0 (X11; Linux x86_64; rv:60.0) Gecko/20100101 Thunderbird/60.7.2 MIME-Version: 1.0 In-Reply-To: <20190806094834.7691-2-imammedo@redhat.com> Content-Type: text/plain; charset=utf-8 Content-Language: en-US X-Scanned-By: MIMEDefang 2.79 on 10.5.11.16 X-Greylist: Sender IP whitelisted, not delayed by milter-greylist-4.5.16 (mx1.redhat.com [10.5.110.47]); Wed, 07 Aug 2019 07:54:29 +0000 (UTC) Content-Transfer-Encoding: quoted-printable X-detected-operating-system: by eggs.gnu.org: GNU/Linux 2.2.x-3.x [generic] X-Received-From: 209.132.183.28 Subject: Re: [Qemu-devel] [qemu-s390x] [PATCH for-4.2 v4 1/2] kvm: s390: split too big memory section on several memslots X-BeenThere: qemu-devel@nongnu.org X-Mailman-Version: 2.1.23 Precedence: list List-Id: List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , Cc: borntraeger@de.ibm.com, thuth@redhat.com, cohuck@redhat.com, qemu-s390x@nongnu.org, pbonzini@redhat.com Errors-To: qemu-devel-bounces+qemu-devel=archiver.kernel.org@nongnu.org Sender: "Qemu-devel" On 06.08.19 11:48, Igor Mammedov wrote: > Max memslot size supported by kvm on s390 is 8Tb, > move logic of splitting RAM in chunks upto 8T to KVM code. >=20 > This way it will hide KVM specific restrictions in KVM code > and won't affect baord level design decisions. Which would allow > us to avoid misusing memory_region_allocate_system_memory() API > and eventually use a single hostmem backend for guest RAM. >=20 > Signed-off-by: Igor Mammedov > --- > v4: > * fix compilation issue > (Christian Borntraeger ) > * advance HVA along with GPA in kvm_set_phys_mem() > (Christian Borntraeger ) >=20 > patch prepares only KVM side for switching to single RAM memory region > another patch will take care of dropping manual RAM partitioning in > s390 code. > --- > include/sysemu/kvm_int.h | 1 + > accel/kvm/kvm-all.c | 80 +++++++++++++++++++++++--------------- > hw/s390x/s390-virtio-ccw.c | 9 ----- > target/s390x/kvm.c | 12 ++++++ > 4 files changed, 62 insertions(+), 40 deletions(-) >=20 > diff --git a/include/sysemu/kvm_int.h b/include/sysemu/kvm_int.h > index 31df465fdc..7f7520bce2 100644 > --- a/include/sysemu/kvm_int.h > +++ b/include/sysemu/kvm_int.h > @@ -41,4 +41,5 @@ typedef struct KVMMemoryListener { > void kvm_memory_listener_register(KVMState *s, KVMMemoryListener *kml, > AddressSpace *as, int as_id); > =20 > +void kvm_set_max_memslot_size(hwaddr max_slot_size); > #endif > diff --git a/accel/kvm/kvm-all.c b/accel/kvm/kvm-all.c > index f450f25295..d87f855ea4 100644 > --- a/accel/kvm/kvm-all.c > +++ b/accel/kvm/kvm-all.c > @@ -138,6 +138,7 @@ bool kvm_direct_msi_allowed; > bool kvm_ioeventfd_any_length_allowed; > bool kvm_msi_use_devid; > static bool kvm_immediate_exit; > +static hwaddr kvm_max_slot_size =3D ~0; > =20 > static const KVMCapabilityInfo kvm_required_capabilites[] =3D { > KVM_CAP_INFO(USER_MEMORY), > @@ -951,6 +952,14 @@ kvm_check_extension_list(KVMState *s, const KVMCap= abilityInfo *list) > return NULL; > } > =20 > +void kvm_set_max_memslot_size(hwaddr max_slot_size) > +{ > + g_assert( > + ROUND_UP(max_slot_size, qemu_real_host_page_size) =3D=3D max_s= lot_size > + ); > + kvm_max_slot_size =3D max_slot_size; > +} > + > static void kvm_set_phys_mem(KVMMemoryListener *kml, > MemoryRegionSection *section, bool add) > { > @@ -958,7 +967,7 @@ static void kvm_set_phys_mem(KVMMemoryListener *kml= , > int err; > MemoryRegion *mr =3D section->mr; > bool writeable =3D !mr->readonly && !mr->rom_device; > - hwaddr start_addr, size; > + hwaddr start_addr, size, slot_size; > void *ram; > =20 > if (!memory_region_is_ram(mr)) { > @@ -983,41 +992,50 @@ static void kvm_set_phys_mem(KVMMemoryListener *k= ml, > kvm_slots_lock(kml); > =20 > if (!add) { > - mem =3D kvm_lookup_matching_slot(kml, start_addr, size); > - if (!mem) { > - goto out; > - } > - if (mem->flags & KVM_MEM_LOG_DIRTY_PAGES) { > - kvm_physical_sync_dirty_bitmap(kml, section); > - } > + do { > + slot_size =3D kvm_max_slot_size < size ? kvm_max_slot_size= : size; > + mem =3D kvm_lookup_matching_slot(kml, start_addr, slot_siz= e); > + if (!mem) { > + goto out; I wonder if this can trigger for the first, but not the second slot (or the other way around). In that case you would want to continue the loop (incrementing counters). But most probably there would something be wrong in the caller if that would happen. > + } > + if (mem->flags & KVM_MEM_LOG_DIRTY_PAGES) { > + kvm_physical_sync_dirty_bitmap(kml, section); > + } > =20 > - /* unregister the slot */ > - g_free(mem->dirty_bmap); > - mem->dirty_bmap =3D NULL; > - mem->memory_size =3D 0; > - mem->flags =3D 0; > - err =3D kvm_set_user_memory_region(kml, mem, false); > - if (err) { > - fprintf(stderr, "%s: error unregistering slot: %s\n", > - __func__, strerror(-err)); > - abort(); > - } > + /* unregister the slot */ > + g_free(mem->dirty_bmap); > + mem->dirty_bmap =3D NULL; > + mem->memory_size =3D 0; > + mem->flags =3D 0; > + err =3D kvm_set_user_memory_region(kml, mem, false); > + if (err) { > + fprintf(stderr, "%s: error unregistering slot: %s\n", > + __func__, strerror(-err)); > + abort(); > + } > + start_addr +=3D slot_size; > + } while ((size -=3D slot_size)); NIT: I think you can drop parentheses - but I would really prefer to not perform computations in the condition. > goto out; > } > =20 > /* register the new slot */ > - mem =3D kvm_alloc_slot(kml); > - mem->memory_size =3D size; > - mem->start_addr =3D start_addr; > - mem->ram =3D ram; > - mem->flags =3D kvm_mem_flags(mr); > - > - err =3D kvm_set_user_memory_region(kml, mem, true); > - if (err) { > - fprintf(stderr, "%s: error registering slot: %s\n", __func__, > - strerror(-err)); > - abort(); > - } > + do { > + slot_size =3D kvm_max_slot_size < size ? kvm_max_slot_size : s= ize; > + mem =3D kvm_alloc_slot(kml); > + mem->memory_size =3D slot_size; > + mem->start_addr =3D start_addr; > + mem->ram =3D ram; > + mem->flags =3D kvm_mem_flags(mr); > + > + err =3D kvm_set_user_memory_region(kml, mem, true); > + if (err) { > + fprintf(stderr, "%s: error registering slot: %s\n", __func= __, > + strerror(-err)); > + abort(); > + } > + start_addr +=3D slot_size; > + ram +=3D slot_size; > + } while ((size -=3D slot_size)); dito One note: KVMState stores the number of slots in "nr_slots". We export that via kvm_get_max_memslots(). E.g., spapr uses that to compare it against "machine->ram_slots". Later (esp. for s390x), kvm_get_max_memslots() can no longer be compared to ram_slots directly. Could be that a ram slot would map to multiple KVM memory slots. There would be no easy way to detect if KVM is able to deal with "machine->ram_slots" as defined by the user, until the sizes of the slots are known. --=20 Thanks, David / dhildenb