Kernel/VirtIO: Remove lazy allocation of VirtIO::Device BAR regions

This fixes a Kernel Panic where the lazy allocation triggers inside an
ISR and grabs a mutex, which isn't allowed when interrupts are
disabled. This also fixes a bug where the mapping for VirtIO device
BARs is never allocated. SerenityOS#9876

Kernel/Bus/VirtIO/Device.cpp

@@ -125,6 +125,18 @@ UNMAP_AFTER_INIT void Device::initialize()
  }
 
  if (m_use_mmio) {
+ for (auto& cfg : m_configs) {
+ auto& mapping = m_mmio[cfg.bar];
+ mapping.size = PCI::get_BAR_space_size(pci_address(), cfg.bar);
+ if (!mapping.base && mapping.size) {
+ auto region_or_error = MM.allocate_kernel_region(PhysicalAddress(page_base_of(PCI::get_BAR(pci_address(), cfg.bar))), Memory::page_round_up(mapping.size), "VirtIO MMIO", Memory::Region::Access::ReadWrite, Memory::Region::Cacheable::No);
+ if (region_or_error.is_error()) {
+ dbgln_if(VIRTIO_DEBUG, "{}: Failed to map bar {} - (size={}) {}", VirtIO::determine_device_class(pci_address()), cfg.bar, mapping.size, region_or_error.error());
+ } else {
+ mapping.base = region_or_error.release_value();
+ }
+ }
+ }
  m_common_cfg = get_config(ConfigurationType::Common, 0);
  m_notify_cfg = get_config(ConfigurationType::Notify, 0);
  m_isr_cfg = get_config(ConfigurationType::ISR, 0);
@@ -147,17 +159,7 @@ UNMAP_AFTER_INIT VirtIO::Device::Device(PCI::Address address)
 auto Device::mapping_for_bar(u8 bar) -> MappedMMIO&
 {
  VERIFY(m_use_mmio);
- auto& mapping = m_mmio[bar];
- if (!mapping.base && mapping.size) {
- auto region_or_error = MM.allocate_kernel_region(PhysicalAddress(page_base_of(PCI::get_BAR(pci_address(), bar))), Memory::page_round_up(mapping.size), "VirtIO MMIO", Memory::Region::Access::ReadWrite, Memory::Region::Cacheable::No);
- if (region_or_error.is_error()) {
- dbgln("{}: Failed to map bar {} - (size={}) {}", VirtIO::determine_device_class(pci_address()), bar, mapping.size, region_or_error.error());
- } else {
- mapping.size = PCI::get_BAR_space_size(pci_address(), bar);
- mapping.base = region_or_error.release_value();
- }
- }
- return mapping;
+ return m_mmio[bar];
 }
 
 void Device::notify_queue(u16 queue_index)