Il 28/03/2013 10:04, Michael S. Tsirkin ha scritto: >>> > > Got ranges_overlap for vq: 0 ring_phys: 0 ring_size: 1028 >>> > > Checking vq: 1 ring_phys: 0 ring_size: 1028 >>>>>>>>>>>>>>>>>>. >>> > > Got ranges_overlap for vq: 1 ring_phys: 0 ring_size: 1028 >>> > > Checking vq: 2 ring_phys: ed000 ring_size: 5124 >>>>>>>>>>>>>>>>>>. >>> > > Calling l: 5124 for start_addr: c0000 for vq 2 >>> > > Unable to map ring buffer for ring 2 >>> > > l: 4096 ring_size: 5124 > okay so the ring address is within ROM. > Unsurprisingly it fails. > bios should stop device before write protect. > The above log is very early, when everything is RAM: vhost_set_memory: section: 0x7fe2801f2b60 section->size: 2146697216 add: 0 Before vhost_verify_ring_mappings: start_addr: c0000 size: 2146697216 The rings are not within ROM. ROM is at 0xc0000-0xcc000 according to the PAM registers. The way I followed the debug output, "Got ranges_overlap" means actually "bailing out because ranges do not overlap". In particular, here all three virtqueues fail the test, because this is the ROM area 0xc0000..0xc7fff: vhost_set_memory: section: 0x7fe2801f2aa0 section->size: 32768 add: 1 Before vhost_verify_ring_mappings: start_addr: c0000 size: 32768 Checking vq: 0 ring_phys: 0 ring_size: 1028 >>>>>>>>>>>>>>>>>>. Got ranges_overlap for vq: 0 ring_phys: 0 ring_size: 1028 Checking vq: 1 ring_phys: 0 ring_size: 1028 >>>>>>>>>>>>>>>>>>. Got ranges_overlap for vq: 1 ring_phys: 0 ring_size: 1028 Checking vq: 2 ring_phys: ed000 ring_size: 5124 >>>>>>>>>>>>>>>>>>. Got ranges_overlap for vq: 2 ring_phys: ed000 ring_size: 5124 Just below, vhost looks at the large RAM area starting at 0xc8000 (it's large because 0xf0000..0xfffff is still RAM): vhost_set_memory: section: 0x7fe2801f2aa0 section->size: 2146664448 add: 1 Before vhost_verify_ring_mappings: start_addr: c8000 size: 2146664448 Checking vq: 0 ring_phys: 0 ring_size: 1028 >>>>>>>>>>>>>>>>>>. Got ranges_overlap for vq: 0 ring_phys: 0 ring_size: 1028 Checking vq: 1 ring_phys: 0 ring_size: 1028 >>>>>>>>>>>>>>>>>>. Got ranges_overlap for vq: 1 ring_phys: 0 ring_size: 1028 Checking vq: 2 ring_phys: ed000 ring_size: 5124 >>>>>>>>>>>>>>>>>>. Calling l: 5124 for start_addr: c8000 for vq 2 Here vq 0 and 1 fail the test because they are in low RAM, vq 2 passes. After 0xf0000..0xfffff is marked readonly, vhost looks at the RAM between 0xc9000 and 0xf0000: vhost_set_memory: section: 0x7fe2801f2aa0 section->size: 159744 add: 1 Before vhost_verify_ring_mappings: start_addr: c9000 size: 159744 Checking vq: 0 ring_phys: 0 ring_size: 1028 >>>>>>>>>>>>>>>>>>. Got ranges_overlap for vq: 0 ring_phys: 0 ring_size: 1028 Checking vq: 1 ring_phys: 0 ring_size: 1028 >>>>>>>>>>>>>>>>>>. Got ranges_overlap for vq: 1 ring_phys: 0 ring_size: 1028 Checking vq: 2 ring_phys: ed000 ring_size: 5124 >>>>>>>>>>>>>>>>>>. Calling l: 5124 for start_addr: c9000 for vq 2 and the ROM between 0xf0000 and 0xfffff, which no ring overlaps with: vhost_set_memory: section: 0x7fe2801f2aa0 section->size: 65536 add: 1 Before vhost_verify_ring_mappings: start_addr: f0000 size: 65536 Checking vq: 0 ring_phys: 0 ring_size: 1028 >>>>>>>>>>>>>>>>>>. Got ranges_overlap for vq: 0 ring_phys: 0 ring_size: 1028 Checking vq: 1 ring_phys: 0 ring_size: 1028 >>>>>>>>>>>>>>>>>>. Got ranges_overlap for vq: 1 ring_phys: 0 ring_size: 1028 Checking vq: 2 ring_phys: ed000 ring_size: 5124 >>>>>>>>>>>>>>>>>>. Got ranges_overlap for vq: 2 ring_phys: ed000 ring_size: 5124 SeaBIOS is indeed not initializing vqs 0/1 (the control and event queues), so their ring_phys is 0. But the one that is failing is vq 2, the first request queue. Your patch seems good, but shouldn't fix this problem. Paolo -- To unsubscribe from this list: send the line "unsubscribe kvm" in the body of a message to majordomo@xxxxxxxxxxxxxxx More majordomo info at http://vger.kernel.org/majordomo-info.html
