Messages in this thread | | | Date | Wed, 8 Dec 2021 13:04:20 -0500 | Subject | Re: [PATCH 23/32] KVM: s390: pci: handle refresh of PCI translations | From | Matthew Rosato <> |
| |
On 12/8/21 5:30 AM, Niklas Schnelle wrote: > On Tue, 2021-12-07 at 15:57 -0500, Matthew Rosato wrote: >> Add a routine that will perform a shadow operation between a guest >> and host IOAT. A subsequent patch will invoke this in response to >> an 04 RPCIT instruction intercept. >> >> Signed-off-by: Matthew Rosato <mjrosato@linux.ibm.com> >> --- >> arch/s390/include/asm/kvm_pci.h | 1 + >> arch/s390/include/asm/pci_dma.h | 1 + >> arch/s390/kvm/pci.c | 191 ++++++++++++++++++++++++++++++++ >> arch/s390/kvm/pci.h | 4 +- >> 4 files changed, 196 insertions(+), 1 deletion(-) >> >> diff --git a/arch/s390/include/asm/kvm_pci.h b/arch/s390/include/asm/kvm_pci.h >> index 254275399f21..97e3a369135d 100644 >> --- a/arch/s390/include/asm/kvm_pci.h >> +++ b/arch/s390/include/asm/kvm_pci.h >> @@ -30,6 +30,7 @@ struct kvm_zdev_ioat { >> struct kvm_zdev { >> struct zpci_dev *zdev; >> struct kvm *kvm; >> + u64 rpcit_count; >> struct kvm_zdev_ioat ioat; >> struct zpci_fib fib; >> }; >> diff --git a/arch/s390/include/asm/pci_dma.h b/arch/s390/include/asm/pci_dma.h >> index e1d3c1d3fc8a..0ca15e5db3d9 100644 >> --- a/arch/s390/include/asm/pci_dma.h >> +++ b/arch/s390/include/asm/pci_dma.h >> @@ -52,6 +52,7 @@ enum zpci_ioat_dtype { >> #define ZPCI_TABLE_ENTRIES (ZPCI_TABLE_SIZE / ZPCI_TABLE_ENTRY_SIZE) >> #define ZPCI_TABLE_PAGES (ZPCI_TABLE_SIZE >> PAGE_SHIFT) >> #define ZPCI_TABLE_ENTRIES_PAGES (ZPCI_TABLE_ENTRIES * ZPCI_TABLE_PAGES) >> +#define ZPCI_TABLE_ENTRIES_PER_PAGE (ZPCI_TABLE_ENTRIES / ZPCI_TABLE_PAGES) >> >> #define ZPCI_TABLE_BITS 11 >> #define ZPCI_PT_BITS 8 >> diff --git a/arch/s390/kvm/pci.c b/arch/s390/kvm/pci.c >> index a1c0c0881332..858c5ecdc8b9 100644 >> --- a/arch/s390/kvm/pci.c >> +++ b/arch/s390/kvm/pci.c >> @@ -123,6 +123,195 @@ int kvm_s390_pci_aen_init(u8 nisc) >> return rc; >> } >> >> +static int dma_shadow_cpu_trans(struct kvm_vcpu *vcpu, unsigned long *entry, >> + unsigned long *gentry) >> +{ >> + unsigned long idx; >> + struct page *page; >> + void *gaddr = NULL; >> + kvm_pfn_t pfn; >> + gpa_t addr; >> + int rc = 0; >> + >> + if (pt_entry_isvalid(*gentry)) { >> + /* pin and validate */ >> + addr = *gentry & ZPCI_PTE_ADDR_MASK; >> + idx = srcu_read_lock(&vcpu->kvm->srcu); >> + page = gfn_to_page(vcpu->kvm, gpa_to_gfn(addr)); >> + srcu_read_unlock(&vcpu->kvm->srcu, idx); >> + if (is_error_page(page)) >> + return -EIO; >> + gaddr = page_to_virt(page) + (addr & ~PAGE_MASK); > > Hmm, this looks like a virtual vs physical address mixup to me that is > currently not a problem because kernel virtual addresses are equal to > their physical address. Here page_to_virt(page) gives us a virtual > address but the entries in the I/O translation table have to be > physical (aka absolute) addresses. > > With my commit "s390/pci: use physical addresses in DMA tables" > currently in the s390 feature branch this is also reflected in the > argument types taken by set_pt_pfaa() below so gaddr should have type > phys_addr_t not void *. That should also remove the need for the cast > to unsigned long for the duplicate check.
Right... Like the other comment re: virtual vs physical address I will take a look and fix for v2.
| |