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@xxxxxxxxxxxxx>
---
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.
