| Message ID | 20240418110140.62406-1-imbrenda@linux.ibm.com (mailing list archive) |
|---|---|
| State | New, archived |
| Headers | show |
| Series | [v1,1/1] lib: s390: fix guest length in uv_create_guest() | expand |
Quoting Claudio Imbrenda (2024-04-18 13:01:40) > The current code creates secure guests with significantly more memory > than expected, but since none of that memory is ever touched, > everything still works. > > Fix the issue by specifying the actual guest length. > > The MSL does not contain the length of the guest, but the address of > the last 1M block of guest memory. In order to get the length, MSO > needs to be subtracted, and 1M needs to be added. > > Signed-off-by: Claudio Imbrenda <imbrenda@linux.ibm.com> Reviewed-by: Nico Boehr <nrb@linux.ibm.com>
Quoting Claudio Imbrenda (2024-04-18 13:01:40) > The current code creates secure guests with significantly more memory > than expected, but since none of that memory is ever touched, > everything still works. > > Fix the issue by specifying the actual guest length. > > The MSL does not contain the length of the guest, but the address of > the last 1M block of guest memory. In order to get the length, MSO > needs to be subtracted, and 1M needs to be added. > > Signed-off-by: Claudio Imbrenda <imbrenda@linux.ibm.com> Pushed to CI and queued, thanks.
diff --git a/lib/s390x/uv.c b/lib/s390x/uv.c index 23a86179..723bb4f2 100644 --- a/lib/s390x/uv.c +++ b/lib/s390x/uv.c @@ -146,7 +146,7 @@ void uv_create_guest(struct vm *vm) int cc; uvcb_cgc.guest_stor_origin = vm->sblk->mso; - uvcb_cgc.guest_stor_len = vm->sblk->msl; + uvcb_cgc.guest_stor_len = vm->sblk->msl - vm->sblk->mso + SZ_1M; /* Config allocation */ vsize = uvcb_qui.conf_base_virt_stor_len +
The current code creates secure guests with significantly more memory than expected, but since none of that memory is ever touched, everything still works. Fix the issue by specifying the actual guest length. The MSL does not contain the length of the guest, but the address of the last 1M block of guest memory. In order to get the length, MSO needs to be subtracted, and 1M needs to be added. Signed-off-by: Claudio Imbrenda <imbrenda@linux.ibm.com> --- lib/s390x/uv.c | 2 +- 1 file changed, 1 insertion(+), 1 deletion(-)