runq_tickle() picks an idle pCPU without taking CSCHED2_MIGRATE_RESIST
into account, but runq_candidate() on that pCPU still applies it. With
the unit's credit within CSCHED2_MIGRATE_RESIST of CSCHED2_CREDIT_MIN,
the tickled pCPU declines the unit because it is not its master, while
the master has already skipped it as deferred to the tickled pCPU. Both
go idle and the unit stays runnable on the runqueue with nobody to run
it.
Seen as a permanent PVH dom0 stall under nested virtualization, where
dom0 overruns its slice far enough to be clamped at CSCHED2_CREDIT_MIN.
Don't resist migration to the pCPU that was tickled for the unit.
Fixes: 069cf39fb1 ("xen: credit2: make tickling more deterministic")
Signed-off-by: Jiaqing Zhao <Zhao.Jiaqing@amd.com>
Reviewed-by: George Dunlap <gwd@xenproject.org>
Reviewed-by: Juergen Gross <jgross@suse.com>
Reviewed-by: Jason Andryuk <jason.andryuk@amd.com>
Hypervisor leaf 5 is PV-specific, but is gated with !is_hvm_domain(),
which stays a runtime test in a build without PV support. Test for a
PV domain directly so the compiler can discard the leaf when
CONFIG_PV is disabled.
Suggested-by: Roger Pau Monné <roger@xenproject.org>
Signed-off-by: Jiaqing Zhao <Zhao.Jiaqing@amd.com>
Reviewed-by: Jan Beulich <jbeulich@suse.com>
Add a PCI device table entry and matching parameter for the ASIX
AX99100 PCIe to Multi-I/O controller [125b:9910]. Each port on the
chip is a standalone PCI function, with UART registers on its I/O
BAR0.
Signed-off-by: Jiaqing Zhao <Zhao.Jiaqing@amd.com>
Reviewed-by: Stefano Stabellini <sstabellini@kernel.org>
Acked-by: Roger Pau Monné <roger.pau@citrix.com>
Add support for the WCH (Nanjing Qinheng Microelectronics Co., Ltd.)
CH382 PCIe dual port serial adapter. The CH382 is available in two
variants:
- CH382 2S [1c00:3253]: 2 serial ports
- CH382 2S1P [1c00:3250]: 2 serial ports + 1 parallel port
This chip uses IO BAR0, base baud rate 115200, ports starting at offset
0xc0 and spaced 8 bytes apart, and a 256-byte FIFO. [1]
[1] https://www.wch-ic.com/downloads/CH382DS1_PDF.html
Signed-off-by: Jiaqing Zhao <Zhao.Jiaqing@amd.com>
Reviewed-by: Denis Mukhin <dmukhin@ford.com>
Reviewed-by: Stefano Stabellini <sstabellini@kernel.org>
Acked-by: Roger Pau Monné <roger.pau@citrix.com>
.bar0 and .mmio in struct ns16550_config_param are booleans, hence they
should be initialized with "true", not "1". No functional change.
Signed-off-by: Jiaqing Zhao <Zhao.Jiaqing@amd.com>
Reviewed-by: Denis Mukhin <dmukhin@ford.com>
Acked-by: Jan Beulich <jbeulich@suse.com>
Jiaqing Zhao