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Commit 86ab8cffb498077e926957f099b064db3751c1de

Authored by Xiao Guangrong
Committed by Avi Kivity
1 parent 037d92dc5d
Exists in smarc-l5.0.0_1.0.0-ga and in 5 other branches imx_3.10.17_1.0.1_ga, imx_3.10.53_1.1.0_ga, imx_3.14.28_1.0.0_ga, smarc-imx_3.10.53_1.1.0_ga, smarc-imx_3.14.28_1.0.0_ga

KVM: introduce gfn_to_hva_read/kvm_read_hva/kvm_read_hva_atomic 

This set of functions is only used to read data from host space, in the
later patch, we will only get a readonly hva in gfn_to_hva_read, and
the function name is a good hint to let gfn_to_hva_read to pair with
kvm_read_hva()/kvm_read_hva_atomic()

Signed-off-by: Xiao Guangrong <xiaoguangrong@linux.vnet.ibm.com>
Signed-off-by: Avi Kivity <avi@redhat.com>

Showing 1 changed file with 23 additions and 4 deletions Side-by-side Diff

... ... @@ -1002,6 +1002,25 @@
1002 1002 }
1003 1003 EXPORT_SYMBOL_GPL(gfn_to_hva);
1004 1004  
  1005 +/*
  1006 + * The hva returned by this function is only allowed to be read.
  1007 + * It should pair with kvm_read_hva() or kvm_read_hva_atomic().
  1008 + */
  1009 +static unsigned long gfn_to_hva_read(struct kvm *kvm, gfn_t gfn)
  1010 +{
  1011 + return gfn_to_hva_many(gfn_to_memslot(kvm, gfn), gfn, NULL);
  1012 +}
  1013 +
  1014 +static int kvm_read_hva(void *data, void __user *hva, int len)
  1015 +{
  1016 + return __copy_from_user(data, hva, len);
  1017 +}
  1018 +
  1019 +static int kvm_read_hva_atomic(void *data, void __user *hva, int len)
  1020 +{
  1021 + return __copy_from_user_inatomic(data, hva, len);
  1022 +}
  1023 +
1005 1024 int get_user_page_nowait(struct task_struct *tsk, struct mm_struct *mm,
1006 1025 unsigned long start, int write, struct page **page)
1007 1026 {
1008 1027  
... ... @@ -1274,10 +1293,10 @@
1274 1293 int r;
1275 1294 unsigned long addr;
1276 1295  
1277   - addr = gfn_to_hva(kvm, gfn);
  1296 + addr = gfn_to_hva_read(kvm, gfn);
1278 1297 if (kvm_is_error_hva(addr))
1279 1298 return -EFAULT;
1280   - r = __copy_from_user(data, (void __user *)addr + offset, len);
  1299 + r = kvm_read_hva(data, (void __user *)addr + offset, len);
1281 1300 if (r)
1282 1301 return -EFAULT;
1283 1302 return 0;
1284 1303  
... ... @@ -1312,11 +1331,11 @@
1312 1331 gfn_t gfn = gpa >> PAGE_SHIFT;
1313 1332 int offset = offset_in_page(gpa);
1314 1333  
1315   - addr = gfn_to_hva(kvm, gfn);
  1334 + addr = gfn_to_hva_read(kvm, gfn);
1316 1335 if (kvm_is_error_hva(addr))
1317 1336 return -EFAULT;
1318 1337 pagefault_disable();
1319   - r = __copy_from_user_inatomic(data, (void __user *)addr + offset, len);
  1338 + r = kvm_read_hva_atomic(data, (void __user *)addr + offset, len);
1320 1339 pagefault_enable();
1321 1340 if (r)
1322 1341 return -EFAULT;