Description: Linux ioperm bitmap context switching issues
References:
 https://xenbits.xen.org/xsa/advisory-329.html
Notes:
 carnil> Introduced in 22fe5b0439dd ("x86/ioperm: Move TSS bitmap update
 carnil> to exit to user work") in 5.5-rc1.
 carnil> Fixed as well in 5.7.10.
Bugs:
upstream: released (5.8-rc6) [cadfad870154e14f745ec845708bc17d166065f2]
4.19-upstream-stable: N/A "Only affects 5.5 and later"
4.9-upstream-stable: N/A "Only affects 5.5 and later"
sid: released (5.7.10-1) [bugfix/x86/x86-ioperm-Fix-io-bitmap-invalidation-on-Xen-PV.patch]
4.19-buster-security: N/A "Only affects 5.5 and later"
4.9-stretch-security: N/A "Only affects 5.5 and later"