Hi, probing of platform UARTs is a problem for x86 jailhouse non-root cells: Linux doesn't know which UARTs belong to the cell and will probe for all platform UARTs. This crashes the guest if access isn't permitted. Current workarounds (tuning via 8250.nr_uarts) are hacky and limited.
But we do have some flags inside setup_data that indicate availability of UARTs, so simply use it. Ralf since v3: - Link: https://www.mail-archive.com/jailhouse-dev@googlegroups.com/msg07365.html - Address Thomas' comments (and it really looks nicer) - Address Jan's comment on patch 1 and add his Reviewed-by tag since v2: - Link: https://www.mail-archive.com/jailhouse-dev@googlegroups.com/msg07334.html - avoid imbalances of early_memremap and early_memunmap since v1: - Link: https://www.mail-archive.com/jailhouse-dev@googlegroups.com/msg07283.html - setup data version check wasn't really prepared for extensions of the structure. Add a patch that improves the checks. Ralf Ramsauer (2): x86/jailhouse: improve setup data version comparison x86/jailhouse: Only enable platform UARTs if available arch/x86/include/uapi/asm/bootparam.h | 25 +++-- arch/x86/kernel/jailhouse.c | 131 ++++++++++++++++++++------ 2 files changed, 117 insertions(+), 39 deletions(-) -- 2.23.0 -- You received this message because you are subscribed to the Google Groups "Jailhouse" group. To unsubscribe from this group and stop receiving emails from it, send an email to jailhouse-dev+unsubscr...@googlegroups.com. To view this discussion on the web visit https://groups.google.com/d/msgid/jailhouse-dev/20190909151030.152012-1-ralf.ramsauer%40oth-regensburg.de.