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authorMarek Marczykowski-Górecki <marmarek@invisiblethingslab.com>2021-08-26 19:03:42 +0200
committerThomas Gleixner <tglx@linutronix.de>2021-08-27 00:27:15 +0200
commit1a519dc7a73c977547d8b5108d98c6e769c89f4b (patch)
tree5d2ee107adcc64c217d3ed3e904306b08c4e4381
parente22ce8eb631bdc47a4a4ea7ecf4e4ba499db4f93 (diff)
PCI/MSI: Skip masking MSI-X on Xen PV
When running as Xen PV guest, masking MSI-X is a responsibility of the hypervisor. The guest has no write access to the relevant BAR at all - when it tries to, it results in a crash like this: BUG: unable to handle page fault for address: ffffc9004069100c #PF: supervisor write access in kernel mode #PF: error_code(0x0003) - permissions violation RIP: e030:__pci_enable_msix_range.part.0+0x26b/0x5f0 e1000e_set_interrupt_capability+0xbf/0xd0 [e1000e] e1000_probe+0x41f/0xdb0 [e1000e] local_pci_probe+0x42/0x80 (...) The recently introduced function msix_mask_all() does not check the global variable pci_msi_ignore_mask which is set by XEN PV to bypass the masking of MSI[-X] interrupts. Add the check to make this function XEN PV compatible. Fixes: 7d5ec3d36123 ("PCI/MSI: Mask all unused MSI-X entries") Signed-off-by: Marek Marczykowski-Górecki <marmarek@invisiblethingslab.com> Signed-off-by: Thomas Gleixner <tglx@linutronix.de> Acked-by: Bjorn Helgaas <bhelgaas@google.com> Cc: stable@vger.kernel.org Link: https://lore.kernel.org/r/20210826170342.135172-1-marmarek@invisiblethingslab.com
-rw-r--r--drivers/pci/msi.c3
1 files changed, 3 insertions, 0 deletions
diff --git a/drivers/pci/msi.c b/drivers/pci/msi.c
index e5e75331b415..3a9f4f8ad8f9 100644
--- a/drivers/pci/msi.c
+++ b/drivers/pci/msi.c
@@ -776,6 +776,9 @@ static void msix_mask_all(void __iomem *base, int tsize)
u32 ctrl = PCI_MSIX_ENTRY_CTRL_MASKBIT;
int i;
+ if (pci_msi_ignore_mask)
+ return;
+
for (i = 0; i < tsize; i++, base += PCI_MSIX_ENTRY_SIZE)
writel(ctrl, base + PCI_MSIX_ENTRY_VECTOR_CTRL);
}

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