diff mbox series

[RFC,v5,2/3] memory: Skip bad range assertion if notifier is DEVIOTLB type

Message ID 20200824104738.20664-3-eperezma@redhat.com (mailing list archive)
State New, archived
Headers show
Series memory: Delete assertion in memory_region_unregister_iommu_notifier | expand

Commit Message

Eugenio Perez Martin Aug. 24, 2020, 10:47 a.m. UTC
I am able to hit this assertion when a Red Hat 7 guest virtio_net device        
raises an "Invalidation" of all the TLB entries. This happens in the            
guest's startup if 'intel_iommu=on' argument is passed to the guest             
kernel and right IOMMU/ATS devices are declared in qemu's command line.         
                                                                                
Command line:                                                                   
/home/qemu/x86_64-softmmu/qemu-system-x86_64 -name \                            
guest=rhel7-test,debug-threads=on -machine \                                    
pc-q35-5.1,accel=kvm,usb=off,dump-guest-core=off,kernel_irqchip=split \         
-cpu \                                                                          
Broadwell,vme=on,ss=on,vmx=on,f16c=on,rdrand=on,hypervisor=on,arat=on,tsc-adjust=on,umip=on,arch-capabilities=on,xsaveopt=on,pdpe1gb=on,abm=on,skip-l1dfl-vmentry=on,rtm=on,hle=on \
-m 8096 -realtime mlock=off -smp 2,sockets=2,cores=1,threads=1 -uuid \          
d022ecbf-679e-4755-87ce-eb87fc5bbc5d -display none -no-user-config \            
-nodefaults -rtc base=utc,driftfix=slew -global \                               
kvm-pit.lost_tick_policy=delay -no-hpet -no-shutdown -global \                  
ICH9-LPC.disable_s3=1 -global ICH9-LPC.disable_s4=1 -boot strict=on \           
-device intel-iommu,intremap=on,device-iotlb=on -device \                       
pcie-root-port,port=0x8,chassis=1,id=pci.1,bus=pcie.0,multifunction=on,addr=0x1 \
-device \                                                                       
pcie-root-port,port=0x9,chassis=2,id=pci.2,bus=pcie.0,addr=0x1.0x1 \            
-device \                                                                       
pcie-root-port,port=0xa,chassis=3,id=pci.3,bus=pcie.0,addr=0x1.0x2 \            
-device \                                                                       
pcie-root-port,port=0xb,chassis=4,id=pci.4,bus=pcie.0,addr=0x1.0x3 \            
-device \                                                                       
pcie-root-port,port=0xc,chassis=5,id=pci.5,bus=pcie.0,addr=0x1.0x4 \            
-device \                                                                       
pcie-root-port,port=0xd,chassis=6,id=pci.6,bus=pcie.0,addr=0x1.0x5 \            
-device \                                                                       
pcie-root-port,port=0xe,chassis=7,id=pci.7,bus=pcie.0,addr=0x1.0x6 \            
-device qemu-xhci,p2=15,p3=15,id=usb,bus=pci.2,addr=0x0 -device \               
virtio-serial-pci,id=virtio-serial0,bus=pci.3,addr=0x0 -drive \                 
file=/home/virtio-test2.qcow2,format=qcow2,if=none,id=drive-virtio-disk0 \      
-device \                                                                       
virtio-blk-pci,scsi=off,bus=pci.4,addr=0x0,drive=drive-virtio-disk0,id=virtio-disk0,bootindex=1 \
-netdev tap,id=hostnet0,vhost=on,vhostforce=on -device \                        
virtio-net-pci,netdev=hostnet0,id=net0,mac=52:54:00:0d:1d:f2,bus=pci.1,addr=0x0,iommu_platform=on,ats=on \
-device virtio-balloon-pci,id=balloon0,bus=pci.5,addr=0x0 -object \             
rng-random,id=objrng0,filename=/dev/urandom -device \                           
virtio-rng-pci,rng=objrng0,id=rng0,bus=pci.6,addr=0x0 -s -msg \                 
timestamp=on                                                                    
                                                                                
Full backtrace:                                                                 
#0  0x00007ffff521370f in raise () at /lib64/libc.so.6                          
#1  0x00007ffff51fdb25 in abort () at /lib64/libc.so.6                          
#2  0x00007ffff51fd9f9 in _nl_load_domain.cold.0 () at /lib64/libc.so.6         
#3  0x00007ffff520bcc6 in .annobin_assert.c_end () at /lib64/libc.so.6          
#4  0x0000555555888171 in memory_region_notify_one                              
                        (notifier=0x7ffde0487fa8, entry=0x7ffde5dfe200)         
                        at /home/qemu/memory.c:1918                             
#5  0x0000555555888247 in memory_region_notify_iommu                            
                      (iommu_mr=0x555556f6c0b0, iommu_idx=0, entry=...)         
                      at /home/qemu/memory.c:1941                               
#6  0x0000555555951c8d in vtd_process_device_iotlb_desc                         
                            (s=0x555557609000, inv_desc=0x7ffde5dfe2d0)         
                            at /home/qemu/hw/i386/intel_iommu.c:2468            
#7  0x0000555555951e6a in vtd_process_inv_desc (s=0x555557609000)               
                               at /home/qemu/hw/i386/intel_iommu.c:2531         
#8  0x0000555555951fa5 in vtd_fetch_inv_desc (s=0x555557609000)                 
                               at /home/qemu/hw/i386/intel_iommu.c:2563         
#9  0x00005555559520e5 in vtd_handle_iqt_write (s=0x555557609000)               
                               at /home/qemu/hw/i386/intel_iommu.c:2590         
#10 0x0000555555952b45 in vtd_mem_write (opaque=0x555557609000,                 
                               addr=136, val=2688, size=4)                      
                               at /home/qemu/hw/i386/intel_iommu.c:2837         
#11 0x0000555555883e17 in memory_region_write_accessor                          
            (mr=0x555557609330, addr=136, value=0x7ffde5dfe478, size=4,         
            shift=0, mask=4294967295, attrs=...)                                
                                             at /home/qemu/memory.c:483         
#12 0x000055555588401d in access_with_adjusted_size                             
            (addr=136, value=0x7ffde5dfe478, size=4, access_size_min=4,         
            access_size_max=8,                                                  
            access_fn=0x555555883d38 <memory_region_write_accessor>,            
            mr=0x555557609330, attrs=...) at /home/qemu/memory.c:544            
#13 0x0000555555886f37 in memory_region_dispatch_write                          
         (mr=0x555557609330, addr=136, data=2688, op=MO_32, attrs=...)          
                                           at /home/qemu/memory.c:1476          
#14 0x0000555555827a03 in flatview_write_continue                               
                       (fv=0x7ffdd8503150, addr=4275634312, attrs=...,          
                        ptr=0x7ffff7ff0028, len=4, addr1=136, l=4,              
                        mr=0x555557609330) at /home/qemu/exec.c:3146            
#15 0x0000555555827b48 in flatview_write (fv=0x7ffdd8503150,                    
                addr=4275634312, attrs=..., buf=0x7ffff7ff0028, len=4)          
                at /home/qemu/exec.c:3186                                       
#16 0x0000555555827e9d in address_space_write                                   
               (as=0x5555567ca640 <address_space_memory>,                       
               addr=4275634312,                                                 
               attrs=..., buf=0x7ffff7ff0028, len=4)                            
               at /home/qemu/exec.c:3277                                        
#17 0x0000555555827f0a in address_space_rw                                      
           (as=0x5555567ca640 <address_space_memory>, addr=4275634312,          
           attrs=..., buf=0x7ffff7ff0028, len=4, is_write=true)                 
           at /home/qemu/exec.c:3287                                            
#18 0x000055555589b633 in kvm_cpu_exec (cpu=0x555556b65640)                     
                                at /home/qemu/accel/kvm/kvm-all.c:2511          
#19 0x0000555555876ba8 in qemu_kvm_cpu_thread_fn (arg=0x555556b65640)           
                               at /home/qemu/cpus.c:1284                        
#20 0x0000555555dafff1 in qemu_thread_start (args=0x555556b8c3b0)               
                                       at util/qemu-thread-posix.c:521          
#21 0x00007ffff55a62de in start_thread () at /lib64/libpthread.so.0             
#22 0x00007ffff52d7e83 in clone () at /lib64/libc.so.6                          
                                                                                
(gdb) frame 4                                                                   
#4  0x0000555555888171 in memory_region_notify_one                              
                      (notifier=0x7ffde0487fa8, entry=0x7ffde5dfe200)           
                      at /home/qemu/memory.c:1918                               
1918        assert(entry->iova >= notifier->start && entry_end <=               
notifier->end);                                                                 
(gdb) p *entry                                                                  
$1 = {target_as = 0x555556f6c050, iova = 0, translated_addr = 0,                
addr_mask = 18446744073709551615, perm = IOMMU_NONE}                            
--                                                                              
                                                                                
Tested with vhost-net, with a linux bridge to forward packets, and              
with testpmd in both host & guest for vhostuser.                                


Signed-off-by: Eugenio PĂ©rez <eperezma@redhat.com>
---
 hw/virtio/vhost.c     |  2 +-
 include/exec/memory.h |  2 ++
 softmmu/memory.c      | 15 +++++++++++++--
 3 files changed, 16 insertions(+), 3 deletions(-)
diff mbox series

Patch

diff --git a/hw/virtio/vhost.c b/hw/virtio/vhost.c
index 1a1384e7a6..6ca168b47e 100644
--- a/hw/virtio/vhost.c
+++ b/hw/virtio/vhost.c
@@ -729,7 +729,7 @@  static void vhost_iommu_region_add(MemoryListener *listener,
     iommu_idx = memory_region_iommu_attrs_to_index(iommu_mr,
                                                    MEMTXATTRS_UNSPECIFIED);
     iommu_notifier_init(&iommu->n, vhost_iommu_unmap_notify,
-                        IOMMU_NOTIFIER_UNMAP,
+                        IOMMU_NOTIFIER_DEVIOTLB,
                         section->offset_within_region,
                         int128_get64(end),
                         iommu_idx);
diff --git a/include/exec/memory.h b/include/exec/memory.h
index 22c5f564d1..b6c3d39b0f 100644
--- a/include/exec/memory.h
+++ b/include/exec/memory.h
@@ -87,6 +87,8 @@  typedef enum {
     IOMMU_NOTIFIER_UNMAP = 0x1,
     /* Notify entry changes (newly created entries) */
     IOMMU_NOTIFIER_MAP = 0x2,
+    /* Notify changes on device IOTLB entries */
+    IOMMU_NOTIFIER_DEVIOTLB = 0x04,
 } IOMMUNotifierFlag;
 
 #define IOMMU_NOTIFIER_ALL (IOMMU_NOTIFIER_MAP | IOMMU_NOTIFIER_UNMAP)
diff --git a/softmmu/memory.c b/softmmu/memory.c
index 961c25b42f..d75f6fa188 100644
--- a/softmmu/memory.c
+++ b/softmmu/memory.c
@@ -1895,6 +1895,7 @@  void memory_region_notify_iommu_one(IOMMUNotifier *notifier,
 {
     IOMMUNotifierFlag request_flags;
     hwaddr entry_end = entry->iova + entry->addr_mask;
+    IOMMUTLBEntry tmp = *entry;
 
     /*
      * Skip the notification if the notification does not overlap
@@ -1904,16 +1905,26 @@  void memory_region_notify_iommu_one(IOMMUNotifier *notifier,
         return;
     }
 
-    assert(entry->iova >= notifier->start && entry_end <= notifier->end);
+    if (notifier->notifier_flags & IOMMU_NOTIFIER_DEVIOTLB) {
+        /* Crop (iova, addr_mask) to range */
+        tmp.iova = MAX(tmp.iova, notifier->start);
+        tmp.addr_mask = MIN(entry_end, notifier->end) - tmp.iova;
+        /* Confirm no underflow */
+        assert(MIN(entry_end, notifier->end) >= tmp.iova);
+    } else {
+        assert(entry->iova >= notifier->start && entry_end <= notifier->end);
+    }
 
     if (entry->perm & IOMMU_RW) {
         request_flags = IOMMU_NOTIFIER_MAP;
+    } else if (notifier->notifier_flags == IOMMU_NOTIFIER_DEVIOTLB) {
+        request_flags = IOMMU_NOTIFIER_DEVIOTLB;
     } else {
         request_flags = IOMMU_NOTIFIER_UNMAP;
     }
 
     if (notifier->notifier_flags & request_flags) {
-        notifier->notify(notifier, entry);
+        notifier->notify(notifier, &tmp);
     }
 }