From: Yuanhan Liu <yuanhan.liu@linux.intel.com>
To: Maxime Coquelin <maxime.coquelin@redhat.com>
Cc: dev@dpdk.org
Subject: Re: [dpdk-dev] [PATCH 2/6] vhost: get guest/host physical address mappings
Date: Tue, 23 Aug 2016 20:32:11 +0800 [thread overview]
Message-ID: <20160823123211.GK30752@yliu-dev.sh.intel.com> (raw)
In-Reply-To: <13f37c6e-b389-a758-81cd-861db7337e1f@redhat.com>
On Tue, Aug 23, 2016 at 11:58:42AM +0200, Maxime Coquelin wrote:
> >
> >+/* Convert guest physical address to host physical address */
> >+static inline phys_addr_t __attribute__((always_inline))
> >+gpa_to_hpa(struct virtio_net *dev, uint64_t gpa, uint64_t size)
> >+{
> >+ uint32_t i;
> >+ struct guest_page *page;
> >+
> >+ for (i = 0; i < dev->nr_guest_pages; i++) {
> >+ page = &dev->guest_pages[i];
> >+
> >+ if (gpa >= page->guest_phys_addr &&
> >+ gpa + size < page->guest_phys_addr + page->size) {
> Shouldn't be '<=' here?
Oops, you are right.
> >+ return gpa - page->guest_phys_addr +
> >+ page->host_phys_addr;
> >+ }
> >+ }
> >+
> >+ return 0;
> >+}
> >+
> > struct virtio_net_device_ops const *notify_ops;
> > struct virtio_net *get_device(int vid);
> >
> >diff --git a/lib/librte_vhost/vhost_user.c b/lib/librte_vhost/vhost_user.c
> >index d2071fd..045d4f0 100644
> >--- a/lib/librte_vhost/vhost_user.c
> >+++ b/lib/librte_vhost/vhost_user.c
> >@@ -372,6 +372,81 @@ vhost_user_set_vring_base(struct virtio_net *dev,
> > return 0;
> > }
> >
> >+static void
> >+add_one_guest_page(struct virtio_net *dev, uint64_t guest_phys_addr,
> >+ uint64_t host_phys_addr, uint64_t size)
> >+{
> >+ struct guest_page *page;
> >+
> >+ if (dev->nr_guest_pages == dev->max_guest_pages) {
> >+ dev->max_guest_pages *= 2;
> >+ dev->guest_pages = realloc(dev->guest_pages,
> >+ dev->max_guest_pages * sizeof(*page));
>
> Maybe realloc return could be checked?
Yes, I should have done that. Besides, I also forgot to free it at
somewhere. Will fix it.
>
> >+ }
> >+
> >+ page = &dev->guest_pages[dev->nr_guest_pages++];
> >+ page->guest_phys_addr = guest_phys_addr;
> >+ page->host_phys_addr = host_phys_addr;
> >+ page->size = size;
> >+}
> >+
> >+static void
> >+add_guest_pages(struct virtio_net *dev, struct virtio_memory_region *reg,
> >+ uint64_t page_size)
> >+{
> >+ uint64_t reg_size = reg->size;
> >+ uint64_t host_user_addr = reg->host_user_addr;
> >+ uint64_t guest_phys_addr = reg->guest_phys_addr;
> >+ uint64_t host_phys_addr;
> >+ uint64_t size;
> >+ uint32_t pre_read;
> >+
> >+ pre_read = *((uint32_t *)(uintptr_t)host_user_addr);
> >+ host_phys_addr = rte_mem_virt2phy((void *)(uintptr_t)host_user_addr);
> >+ size = page_size - (guest_phys_addr & (page_size - 1));
> >+ size = RTE_MIN(size, reg_size);
> >+
> >+ add_one_guest_page(dev, guest_phys_addr, host_phys_addr, size);
> >+ host_user_addr += size;
> >+ guest_phys_addr += size;
> >+ reg_size -= size;
> >+
> >+ while (reg_size > 0) {
> >+ pre_read += *((uint32_t *)(uintptr_t)host_user_addr);
> >+ host_phys_addr = rte_mem_virt2phy((void *)(uintptr_t)host_user_addr);
> >+ add_one_guest_page(dev, guest_phys_addr, host_phys_addr, page_size);
> >+
> >+ host_user_addr += page_size;
> >+ guest_phys_addr += page_size;
> >+ reg_size -= page_size;
> >+ }
> >+
> >+ /* FIXME */
> >+ RTE_LOG(INFO, VHOST_CONFIG, ":: %u ::\n", pre_read);
> For my information, what is the purpose of pre_read?
Again, I put a FIXME here, but I forgot to add some explanation.
Here is the thing: the read will make sure the kernel populate the
corresponding PTE entry, so that rte_mem_virt2phy() will return proper
physical address, otherwise, invalid value is returned.
I can't simply do the read but do not actually reference/consume it.
Otherwise, the compiler will treat it as some noops and remove it.
An ugly RTE_LOG will make sure the read operation is not eliminated.
I'm seeking a more proper way to achieve that. Maybe I can add a new
field in virtio_net structure and store it there.
Or, do you have better ideas?
--yliu
next prev parent reply other threads:[~2016-08-23 12:22 UTC|newest]
Thread overview: 75+ messages / expand[flat|nested] mbox.gz Atom feed top
2016-08-23 8:10 [dpdk-dev] [PATCH 0/6] vhost: add Tx zero copy support Yuanhan Liu
2016-08-23 8:10 ` [dpdk-dev] [PATCH 1/6] vhost: simplify memory regions handling Yuanhan Liu
2016-08-23 9:17 ` Maxime Coquelin
2016-08-24 7:26 ` Xu, Qian Q
2016-08-24 7:40 ` Yuanhan Liu
2016-08-24 7:36 ` Xu, Qian Q
2016-08-23 8:10 ` [dpdk-dev] [PATCH 2/6] vhost: get guest/host physical address mappings Yuanhan Liu
2016-08-23 9:58 ` Maxime Coquelin
2016-08-23 12:32 ` Yuanhan Liu [this message]
2016-08-23 13:25 ` Maxime Coquelin
2016-08-23 13:49 ` Yuanhan Liu
2016-08-23 14:05 ` Maxime Coquelin
2016-08-23 8:10 ` [dpdk-dev] [PATCH 3/6] vhost: introduce last avail idx for Tx Yuanhan Liu
2016-08-23 12:27 ` Maxime Coquelin
2016-08-23 8:10 ` [dpdk-dev] [PATCH 4/6] vhost: add Tx zero copy Yuanhan Liu
2016-08-23 14:04 ` Maxime Coquelin
2016-08-23 14:31 ` Yuanhan Liu
2016-08-23 15:40 ` Maxime Coquelin
2016-08-23 8:10 ` [dpdk-dev] [PATCH 5/6] vhost: add a flag to enable " Yuanhan Liu
2016-09-06 9:00 ` Xu, Qian Q
2016-09-06 9:42 ` Xu, Qian Q
2016-09-06 10:02 ` Yuanhan Liu
2016-09-07 2:43 ` Xu, Qian Q
2016-09-06 9:55 ` Yuanhan Liu
2016-09-07 16:00 ` Thomas Monjalon
2016-09-08 7:21 ` Yuanhan Liu
2016-09-08 7:57 ` Thomas Monjalon
2016-08-23 8:10 ` [dpdk-dev] [PATCH 6/6] examples/vhost: add an option " Yuanhan Liu
2016-08-23 9:31 ` Thomas Monjalon
2016-08-23 12:33 ` Yuanhan Liu
2016-08-23 14:14 ` Maxime Coquelin
2016-08-23 14:45 ` Yuanhan Liu
2016-08-23 14:18 ` [dpdk-dev] [PATCH 0/6] vhost: add Tx zero copy support Maxime Coquelin
2016-08-23 14:42 ` Yuanhan Liu
2016-08-23 14:53 ` Yuanhan Liu
2016-08-23 16:41 ` Maxime Coquelin
2016-08-29 8:32 ` Xu, Qian Q
2016-08-29 8:57 ` Xu, Qian Q
2016-09-23 4:11 ` Yuanhan Liu
2016-10-09 15:20 ` Yuanhan Liu
2016-09-23 4:13 ` [dpdk-dev] [PATCH v2 0/7] vhost: add dequeue " Yuanhan Liu
2016-09-23 4:13 ` [dpdk-dev] [PATCH v2 1/7] vhost: simplify memory regions handling Yuanhan Liu
2016-09-23 4:13 ` [dpdk-dev] [PATCH v2 2/7] vhost: get guest/host physical address mappings Yuanhan Liu
2016-09-26 20:17 ` Maxime Coquelin
2016-09-23 4:13 ` [dpdk-dev] [PATCH v2 3/7] vhost: introduce last avail idx for dequeue Yuanhan Liu
2016-09-23 4:13 ` [dpdk-dev] [PATCH v2 4/7] vhost: add dequeue zero copy Yuanhan Liu
2016-09-26 20:45 ` Maxime Coquelin
2016-10-06 14:37 ` Xu, Qian Q
2016-10-09 2:03 ` Yuanhan Liu
2016-10-10 10:12 ` Xu, Qian Q
2016-10-10 10:14 ` Maxime Coquelin
2016-10-10 10:22 ` Xu, Qian Q
2016-10-10 10:40 ` Xu, Qian Q
2016-10-10 11:48 ` Maxime Coquelin
2016-09-23 4:13 ` [dpdk-dev] [PATCH v2 5/7] vhost: add a flag to enable " Yuanhan Liu
2016-09-26 20:57 ` Maxime Coquelin
2016-09-23 4:13 ` [dpdk-dev] [PATCH v2 6/7] examples/vhost: add an option " Yuanhan Liu
2016-09-26 21:05 ` Maxime Coquelin
2016-09-23 4:13 ` [dpdk-dev] [PATCH v2 7/7] net/vhost: " Yuanhan Liu
2016-09-26 21:05 ` Maxime Coquelin
2016-10-09 7:27 ` [dpdk-dev] [PATCH v3 0/7] vhost: add dequeue zero copy support Yuanhan Liu
2016-10-09 7:27 ` [dpdk-dev] [PATCH v3 1/7] vhost: simplify memory regions handling Yuanhan Liu
2016-10-09 7:27 ` [dpdk-dev] [PATCH v3 2/7] vhost: get guest/host physical address mappings Yuanhan Liu
2016-11-29 3:10 ` linhaifeng
2016-11-29 13:14 ` linhaifeng
2016-10-09 7:27 ` [dpdk-dev] [PATCH v3 3/7] vhost: introduce last avail idx for dequeue Yuanhan Liu
2016-10-09 7:27 ` [dpdk-dev] [PATCH v3 4/7] vhost: add dequeue zero copy Yuanhan Liu
2016-10-09 7:27 ` [dpdk-dev] [PATCH v3 5/7] vhost: add a flag to enable " Yuanhan Liu
2016-10-09 7:27 ` [dpdk-dev] [PATCH v3 6/7] examples/vhost: add an option " Yuanhan Liu
2016-10-09 7:28 ` [dpdk-dev] [PATCH v3 7/7] net/vhost: " Yuanhan Liu
2016-10-11 13:04 ` [dpdk-dev] [PATCH v3 0/7] vhost: add dequeue zero copy support Xu, Qian Q
2016-10-12 7:48 ` Yuanhan Liu
2016-10-09 10:46 ` [dpdk-dev] [PATCH 0/6] vhost: add Tx " linhaifeng
2016-10-10 8:03 ` Yuanhan Liu
2016-10-14 7:30 ` linhaifeng
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