[Date Prev][Date Next][Thread Prev][Thread Next][Date Index][Thread Index] [xen master] vpci/msix: restore PBA access length and alignment restrictions
commit 7a502b4fbc339e9d3d3d45fb37f09da06bc3081c Author: Roger Pau Monné <roger.pau@xxxxxxxxxx> AuthorDate: Wed Mar 29 14:56:33 2023 +0200 Commit: Jan Beulich <jbeulich@xxxxxxxx> CommitDate: Wed Mar 29 14:56:33 2023 +0200 vpci/msix: restore PBA access length and alignment restrictions Accesses to the PBA array have the same length and alignment limitations as accesses to the MSI-X table: "For all accesses to MSI-X Table and MSI-X PBA fields, software must use aligned full DWORD or aligned full QWORD transactions; otherwise, the result is undefined." Introduce such length and alignment checks into the handling of PBA accesses for vPCI. This was a mistake of mine for not reading the specification correctly. Note that accesses must now be aligned, and hence there's no longer a need to check that the end of the access falls into the PBA region as both the access and the region addresses must be aligned. Fixes: b177892d2d ('vpci/msix: handle accesses adjacent to the MSI-X table') Reported-by: Jan Beulich <jbeulich@xxxxxxxx> Signed-off-by: Roger Pau Monné <roger.pau@xxxxxxxxxx> Reviewed-by: Jan Beulich <jbeulich@xxxxxxxx> --- xen/drivers/vpci/msix.c | 10 +++++++--- 1 file changed, 7 insertions(+), 3 deletions(-) diff --git a/xen/drivers/vpci/msix.c b/xen/drivers/vpci/msix.c index 99dd249c15..25bde77586 100644 --- a/xen/drivers/vpci/msix.c +++ b/xen/drivers/vpci/msix.c @@ -278,6 +278,11 @@ static int adjacent_read(const struct domain *d, const struct vpci_msix *msix, if ( !adjacent_handle(msix, addr + len - 1) ) return X86EMUL_OKAY; + if ( VMSIX_ADDR_IN_RANGE(addr, vpci, VPCI_MSIX_PBA) && + !access_allowed(msix->pdev, addr, len) ) + /* PBA accesses must be aligned and 4 or 8 bytes in size. */ + return X86EMUL_OKAY; + slot = get_slot(vpci, addr); if ( slot >= ARRAY_SIZE(msix->table) ) return X86EMUL_OKAY; @@ -419,9 +424,8 @@ static int adjacent_write(const struct domain *d, const struct vpci_msix *msix, * assumed to be equal or bigger (8 bytes) than the length of any access * handled here. */ - if ( (VMSIX_ADDR_IN_RANGE(addr, vpci, VPCI_MSIX_PBA) || - VMSIX_ADDR_IN_RANGE(addr + len - 1, vpci, VPCI_MSIX_PBA)) && - !is_hardware_domain(d) ) + if ( VMSIX_ADDR_IN_RANGE(addr, vpci, VPCI_MSIX_PBA) && + (!access_allowed(msix->pdev, addr, len) || !is_hardware_domain(d)) ) /* Ignore writes to PBA for DomUs, it's undefined behavior. */ return X86EMUL_OKAY; -- generated by git-patchbot for /home/xen/git/xen.git#master
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