[PATCH v4 2/4] PCI/MSI: Check msi_addr_mask in msi_verify_entries()

Vivian Wang
2026-01-29T01:56:53Z

Instead of a 32-bit/64-bit dichotomy, check the MSI address against
msi_addr_mask.

This allows platforms with an MSI doorbell address above the 32-bit
limit to work with devices without full 64-bit MSI address support, as
long as the doorbell is within the addressable range of MSI of the
device.

Reviewed-by: Thomas Gleixner <tglx@kernel.org>
Signed-off-by: Vivian Wang <wangruikang@iscas.ac.cn>
---
v4: Patch message rewording, and one code style fix (Thomas)
---
drivers/pci/msi/msi.c | 8 +++++---
1 file changed, 5 insertions(+), 3 deletions(-)

diff --git a/drivers/pci/msi/msi.c b/drivers/pci/msi/msi.c
index 48f5f03d1479..424a4ba9b557 100644
--- a/drivers/pci/msi/msi.c
+++ b/drivers/pci/msi/msi.c
@@ -321,14 +321,16 @@ static int msi_setup_msi_desc(struct pci_dev *dev, int nvec,
static int msi_verify_entries(struct pci_dev *dev)
{
struct msi_desc *entry;
+ u64 address;

if (dev->msi_addr_mask == DMA_BIT_MASK(64))
return 0;

msi_for_each_desc(entry, &dev->dev, MSI_DESC_ALL) {
- if (entry->msg.address_hi) {
- pci_err(dev, "arch assigned 64-bit MSI address %#x%08x but device only supports 32 bits\n",
- entry->msg.address_hi, entry->msg.address_lo);
+ address = (u64)entry->msg.address_hi << 32 | entry->msg.address_lo;
+ if (address & ~dev->msi_addr_mask) {
+ pci_err(dev, "arch assigned 64-bit MSI address %#llx above device MSI address mask %#llx\n",
+ address, dev->msi_addr_mask);
break;
}
}

--
2.52.0