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由 Alexey Kardashevskiy 提交于
On the sPAPR platform a guest allocates MSI/MSIX vectors via RTAS hypercalls which return global IRQ numbers to a guest so it only operates with those and never touches MSIMessage. Therefore MSIMessage handling is completely hidden in QEMU. Previously every sPAPR PCI host bridge implemented its own MSI window to catch msi_notify()/msix_notify() calls from QEMU devices (virtio-pci or vfio) and route them to the guest via qemu_pulse_irq(). MSIMessage used to be encoded as: .addr - address within the PHB MSI window; .data - the device index on PHB plus vector number. The MSI MR write function translated this MSIMessage to a global IRQ number and called qemu_pulse_irq(). However the total number of IRQs is not really big (at the moment it is 1024 IRQs starting from 4096) and even 16bit data field of MSIMessage seems to be enough to store an IRQ number there. This simplifies MSI handling in sPAPR PHB. Specifically, this does: 1. remove a MSI window from a PHB; 2. add a single memory region for all MSIs to sPAPREnvironment and spapr_pci_msi_init() to initialize it; 3. encode MSIMessage as: * .addr - a fixed address of SPAPR_PCI_MSI_WINDOW==0x40000000000ULL; * .data as an IRQ number. 4. change IRQ allocator to align first IRQ number in a block for MSI. MSI uses lower bits to specify the vector number so the first IRQ has to be aligned. MSIX does not need any special allocator though. Signed-off-by: NAlexey Kardashevskiy <aik@ozlabs.ru> Reviewed-by: NAnthony Liguori <aliguori@us.ibm.com> Acked-by: NMichael S. Tsirkin <mst@redhat.com> Signed-off-by: NAlexander Graf <agraf@suse.de>
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