[PULL 20/38] hw/arm/virt: Disable highmem devices that don't fit in the PA range

[Peter Maydell]

From: Marc Zyngier <maz@kernel.org>

In order to only keep the highmem devices that actually fit in
the PA range, check their location against the range and update
highest_gpa if they fit. If they don't, mark them as disabled.

Signed-off-by: Marc Zyngier <maz@kernel.org>
Reviewed-by: Eric Auger <eric.auger@redhat.com>
Message-id: 20220114140741.1358263-6-maz@kernel.org
Signed-off-by: Peter Maydell <peter.maydell@linaro.org>
---
 hw/arm/virt.c | 34 ++++++++++++++++++++++++++++------
 1 file changed, 28 insertions(+), 6 deletions(-)

diff --git a/hw/arm/virt.c b/hw/arm/virt.c
index 8627f5ab953..8d02c2267d0 100644
--- a/hw/arm/virt.c
+++ b/hw/arm/virt.c
@@ -1719,21 +1719,43 @@ static void virt_set_memmap(VirtMachineState *vms, int 
pa_bits)
         base = vms->memmap[VIRT_MEM].base + LEGACY_RAMLIMIT_BYTES;
     }
 
+    /* We know for sure that at least the memory fits in the PA space */
+    vms->highest_gpa = memtop - 1;
+
     for (i = VIRT_LOWMEMMAP_LAST; i < ARRAY_SIZE(extended_memmap); i++) {
         hwaddr size = extended_memmap[i].size;
+        bool fits;
 
         base = ROUND_UP(base, size);
         vms->memmap[i].base = base;
         vms->memmap[i].size = size;
+
+        /*
+         * Check each device to see if they fit in the PA space,
+         * moving highest_gpa as we go.
+         *
+         * For each device that doesn't fit, disable it.
+         */
+        fits = (base + size) <= BIT_ULL(pa_bits);
+        if (fits) {
+            vms->highest_gpa = base + size - 1;
+        }
+
+        switch (i) {
+        case VIRT_HIGH_GIC_REDIST2:
+            vms->highmem_redists &= fits;
+            break;
+        case VIRT_HIGH_PCIE_ECAM:
+            vms->highmem_ecam &= fits;
+            break;
+        case VIRT_HIGH_PCIE_MMIO:
+            vms->highmem_mmio &= fits;
+            break;
+        }
+
         base += size;
     }
 
-    /*
-     * If base fits within pa_bits, all good. If it doesn't, limit it
-     * to the end of RAM, which is guaranteed to fit within pa_bits.
-     */
-    vms->highest_gpa = (base <= BIT_ULL(pa_bits) ? base : memtop) - 1;
-
     if (device_memory_size > 0) {
         ms->device_memory = g_malloc0(sizeof(*ms->device_memory));
         ms->device_memory->base = device_memory_base;
-- 
2.25.1