kernel.git/arch/powerpc/sysdev/xive/common.c, branch linux-5.7.y

powerpc/xive: Clear the page tables for the ESB IO mapping

2020-06-17T14:42:46Z

[ Upstream commit a101950fcb78b0ba20cd487be6627dea58d55c2b ] Commit 1ca3dec2b2df ("powerpc/xive: Prevent page fault issues in the machine crash handler") fixed an issue in the FW assisted dump of machines using hash MMU and the XIVE interrupt mode under the POWER hypervisor. It forced the mapping of the ESB page of interrupts being mapped in the Linux IRQ number space to make sure the 'crash kexec' sequence worked during such an event. But it didn't handle the un-mapping. This mapping is now blocking the removal of a passthrough IO adapter under the POWER hypervisor because it expects the guest OS to have cleared all page table entries related to the adapter. If some are still present, the RTAS call which isolates the PCI slot returns error 9001 "valid outstanding translations". Remove these mapping in the IRQ data cleanup routine. Under KVM, this cleanup is not required because the ESB pages for the adapter interrupts are un-mapped from the guest by the hypervisor in the KVM XIVE native device. This is now redundant but it's harmless. Fixes: 1ca3dec2b2df ("powerpc/xive: Prevent page fault issues in the machine crash handler") Cc: stable@vger.kernel.org # v5.5+ Signed-off-by: Cédric Le Goater Signed-off-by: Michael Ellerman Link: https://lore.kernel.org/r/20200429075122.1216388-2-clg@kaod.org Signed-off-by: Sasha Levin

powerpc/xive: Add a debugfs file to dump internal XIVE state

2020-03-26T13:20:38Z

As does XMON, the debugfs file /sys/kernel/debug/powerpc/xive exposes the XIVE internal state of the machine CPUs and interrupts. Available on the PowerNV and sPAPR platforms. Signed-off-by: Cédric Le Goater [mpe: Make the debugfs file 0400] Signed-off-by: Michael Ellerman Link: https://lore.kernel.org/r/20200306150143.5551-5-clg@kaod.org

powerpc/xmon: Add source flags to output of XIVE interrupts

2020-03-26T13:19:05Z

Some firmwares or hypervisors can advertise different source characteristics. Track their value under XMON. What we are mostly interested in is the StoreEOI flag. Signed-off-by: Cédric Le Goater Reviewed-by: Greg Kurz Signed-off-by: Michael Ellerman Link: https://lore.kernel.org/r/20200306150143.5551-4-clg@kaod.org

powerpc/xive: Fix xmon support on the PowerNV platform

2020-03-26T13:19:05Z

The PowerNV platform has multiple IRQ chips and the xmon command dumping the state of the XIVE interrupt should only operate on the XIVE IRQ chip. Fixes: 5896163f7f91 ("powerpc/xmon: Improve output of XIVE interrupts") Cc: stable@vger.kernel.org # v5.4+ Signed-off-by: Cédric Le Goater Reviewed-by: Greg Kurz Signed-off-by: Michael Ellerman Link: https://lore.kernel.org/r/20200306150143.5551-3-clg@kaod.org

powerpc/xive: Use XIVE_BAD_IRQ instead of zero to catch non configured IPIs

2020-03-26T13:19:04Z

When a CPU is brought up, an IPI number is allocated and recorded under the XIVE CPU structure. Invalid IPI numbers are tracked with interrupt number 0x0. On the PowerNV platform, the interrupt number space starts at 0x10 and this works fine. However, on the sPAPR platform, it is possible to allocate the interrupt number 0x0 and this raises an issue when CPU 0 is unplugged. The XIVE spapr driver tracks allocated interrupt numbers in a bitmask and it is not correctly updated when interrupt number 0x0 is freed. It stays allocated and it is then impossible to reallocate. Fix by using the XIVE_BAD_IRQ value instead of zero on both platforms. Reported-by: David Gibson Fixes: eac1e731b59e ("powerpc/xive: guest exploitation of the XIVE interrupt controller") Cc: stable@vger.kernel.org # v4.14+ Signed-off-by: Cédric Le Goater Reviewed-by: David Gibson Tested-by: David Gibson Signed-off-by: Michael Ellerman Link: https://lore.kernel.org/r/20200306150143.5551-2-clg@kaod.org

powerpc/xive: Discard ESB load value when interrupt is invalid

2020-01-22T09:31:41Z

A load on an ESB page returning all 1's means that the underlying device has invalidated the access to the PQ state of the interrupt through mmio. It may happen, for example when querying a PHB interrupt while the PHB is in an error state. In that case, we should consider the interrupt to be invalid when checking its state in the irq_get_irqchip_state() handler. Fixes: da15c03b047d ("powerpc/xive: Implement get_irqchip_state method for XIVE to fix shutdown race") Cc: stable@vger.kernel.org # v5.4+ Signed-off-by: Frederic Barrat [clg: wrote a commit log, introduced XIVE_ESB_INVALID ] Signed-off-by: Cédric Le Goater Signed-off-by: Michael Ellerman Link: https://lore.kernel.org/r/20200113130118.27969-1-clg@kaod.org

powerpc/xive: Prevent page fault issues in the machine crash handler

2019-11-13T05:58:10Z

When the machine crash handler is invoked, all interrupts are masked but interrupts which have not been started yet do not have an ESB page mapped in the Linux address space. This crashes the 'crash kexec' sequence on sPAPR guests. To fix, force the mapping of the ESB page when an interrupt is being mapped in the Linux IRQ number space. This is done by setting the initial state of the interrupt to OFF which is not necessarily the case on PowerNV. Fixes: 243e25112d06 ("powerpc/xive: Native exploitation of the XIVE interrupt controller") Cc: stable@vger.kernel.org # v4.12+ Signed-off-by: Cédric Le Goater Reviewed-by: Greg Kurz Signed-off-by: Michael Ellerman Link: https://lore.kernel.org/r/20191031063100.3864-1-clg@kaod.org

powerpc/xmon: Fix output of XIVE IPI

2019-09-13T14:58:47Z

When dumping the XIVE state of an CPU IPI, xmon does not check if the CPU is started or not which can cause an error. Add a check for that and change the output to be on one line just as the XIVE interrupts of the machine. Signed-off-by: Cédric Le Goater Signed-off-by: Michael Ellerman Link: https://lore.kernel.org/r/20190910081850.26038-3-clg@kaod.org

powerpc/xmon: Improve output of XIVE interrupts

2019-09-13T14:58:47Z

When looping on the list of interrupts, add the current value of the PQ bits with a load on the ESB page. This has the side effect of faulting the ESB page of all interrupts. Signed-off-by: Cédric Le Goater Signed-off-by: Michael Ellerman Link: https://lore.kernel.org/r/20190910081850.26038-2-clg@kaod.org

powerpc/xive: Fix dump of XIVE interrupt under pseries

2019-08-19T03:20:24Z

The xmon 'dxi' command calls OPAL to query the XIVE configuration of a interrupt. This can only be done on baremetal (PowerNV) and it will crash a pseries machine. Introduce a new XIVE get_irq_config() operation which implements a different query depending on the platform, PowerNV or pseries, and modify xmon to use a top level wrapper. Signed-off-by: Cédric Le Goater Signed-off-by: Michael Ellerman Link: https://lore.kernel.org/r/20190814154754.23682-3-clg@kaod.org