126 lines
4.3 KiB
Diff
126 lines
4.3 KiB
Diff
From ed90f91b61844abd2dff2eb970f721a6cf072235 Mon Sep 17 00:00:00 2001
|
|
From: Matthew Rosato <mjrosato@linux.ibm.com>
|
|
Date: Fri, 28 Oct 2022 15:47:57 -0400
|
|
Subject: [PATCH 6/9] s390x/pci: coalesce unmap operations
|
|
MIME-Version: 1.0
|
|
Content-Type: text/plain; charset=UTF-8
|
|
Content-Transfer-Encoding: 8bit
|
|
|
|
RH-Author: Cédric Le Goater <clg@redhat.com>
|
|
RH-MergeRequest: 141: s390x/pci: reset ISM passthrough devices on shutdown and system reset
|
|
RH-Bugzilla: 2163701
|
|
RH-Acked-by: Thomas Huth <thuth@redhat.com>
|
|
RH-Acked-by: Cornelia Huck <cohuck@redhat.com>
|
|
RH-Acked-by: Miroslav Rezanina <mrezanin@redhat.com>
|
|
RH-Commit: [1/3] 80c3a2c1d720057ae2a80b338ea06c9c6c804532 (clegoate/qemu-kvm-c9s)
|
|
|
|
Currently, each unmapped page is handled as an individual iommu
|
|
region notification. Attempt to group contiguous unmap operations
|
|
into fewer notifications to reduce overhead.
|
|
|
|
Signed-off-by: Matthew Rosato <mjrosato@linux.ibm.com>
|
|
Message-Id: <20221028194758.204007-3-mjrosato@linux.ibm.com>
|
|
Reviewed-by: Eric Farman <farman@linux.ibm.com>
|
|
Signed-off-by: Thomas Huth <thuth@redhat.com>
|
|
(cherry picked from commit ef536007c3301bbd6a787e4c2210ea289adaa6f0)
|
|
Signed-off-by: Cédric Le Goater <clg@redhat.com>
|
|
---
|
|
hw/s390x/s390-pci-inst.c | 51 ++++++++++++++++++++++++++++++++++++++++
|
|
1 file changed, 51 insertions(+)
|
|
|
|
diff --git a/hw/s390x/s390-pci-inst.c b/hw/s390x/s390-pci-inst.c
|
|
index 7cc4bcf850..66e764f901 100644
|
|
--- a/hw/s390x/s390-pci-inst.c
|
|
+++ b/hw/s390x/s390-pci-inst.c
|
|
@@ -640,6 +640,8 @@ static uint32_t s390_pci_update_iotlb(S390PCIIOMMU *iommu,
|
|
}
|
|
g_hash_table_remove(iommu->iotlb, &entry->iova);
|
|
inc_dma_avail(iommu);
|
|
+ /* Don't notify the iommu yet, maybe we can bundle contiguous unmaps */
|
|
+ goto out;
|
|
} else {
|
|
if (cache) {
|
|
if (cache->perm == entry->perm &&
|
|
@@ -663,15 +665,44 @@ static uint32_t s390_pci_update_iotlb(S390PCIIOMMU *iommu,
|
|
dec_dma_avail(iommu);
|
|
}
|
|
|
|
+ /*
|
|
+ * All associated iotlb entries have already been cleared, trigger the
|
|
+ * unmaps.
|
|
+ */
|
|
memory_region_notify_iommu(&iommu->iommu_mr, 0, event);
|
|
|
|
out:
|
|
return iommu->dma_limit ? iommu->dma_limit->avail : 1;
|
|
}
|
|
|
|
+static void s390_pci_batch_unmap(S390PCIIOMMU *iommu, uint64_t iova,
|
|
+ uint64_t len)
|
|
+{
|
|
+ uint64_t remain = len, start = iova, end = start + len - 1, mask, size;
|
|
+ IOMMUTLBEvent event = {
|
|
+ .type = IOMMU_NOTIFIER_UNMAP,
|
|
+ .entry = {
|
|
+ .target_as = &address_space_memory,
|
|
+ .translated_addr = 0,
|
|
+ .perm = IOMMU_NONE,
|
|
+ },
|
|
+ };
|
|
+
|
|
+ while (remain >= TARGET_PAGE_SIZE) {
|
|
+ mask = dma_aligned_pow2_mask(start, end, 64);
|
|
+ size = mask + 1;
|
|
+ event.entry.iova = start;
|
|
+ event.entry.addr_mask = mask;
|
|
+ memory_region_notify_iommu(&iommu->iommu_mr, 0, event);
|
|
+ start += size;
|
|
+ remain -= size;
|
|
+ }
|
|
+}
|
|
+
|
|
int rpcit_service_call(S390CPU *cpu, uint8_t r1, uint8_t r2, uintptr_t ra)
|
|
{
|
|
CPUS390XState *env = &cpu->env;
|
|
+ uint64_t iova, coalesce = 0;
|
|
uint32_t fh;
|
|
uint16_t error = 0;
|
|
S390PCIBusDevice *pbdev;
|
|
@@ -742,6 +773,21 @@ int rpcit_service_call(S390CPU *cpu, uint8_t r1, uint8_t r2, uintptr_t ra)
|
|
break;
|
|
}
|
|
|
|
+ /*
|
|
+ * If this is an unmap of a PTE, let's try to coalesce multiple unmaps
|
|
+ * into as few notifier events as possible.
|
|
+ */
|
|
+ if (entry.perm == IOMMU_NONE && entry.len == TARGET_PAGE_SIZE) {
|
|
+ if (coalesce == 0) {
|
|
+ iova = entry.iova;
|
|
+ }
|
|
+ coalesce += entry.len;
|
|
+ } else if (coalesce > 0) {
|
|
+ /* Unleash the coalesced unmap before processing a new map */
|
|
+ s390_pci_batch_unmap(iommu, iova, coalesce);
|
|
+ coalesce = 0;
|
|
+ }
|
|
+
|
|
start += entry.len;
|
|
while (entry.iova < start && entry.iova < end) {
|
|
if (dma_avail > 0 || entry.perm == IOMMU_NONE) {
|
|
@@ -759,6 +805,11 @@ int rpcit_service_call(S390CPU *cpu, uint8_t r1, uint8_t r2, uintptr_t ra)
|
|
}
|
|
}
|
|
}
|
|
+ if (coalesce) {
|
|
+ /* Unleash the coalesced unmap before finishing rpcit */
|
|
+ s390_pci_batch_unmap(iommu, iova, coalesce);
|
|
+ coalesce = 0;
|
|
+ }
|
|
if (again && dma_avail > 0)
|
|
goto retry;
|
|
err:
|
|
--
|
|
2.31.1
|
|
|