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Kernel: Implement a naive version of virtconsole by memcpying to physical page

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This patch allocates a physical page for each of the virtqueues and
memcpys to it when receiving a buffer to get a physical, aligned
contiguous buffer as required by the virtio specification.

Co-authored-by: Sahan <sahan.h.fernando@gmail.com>
This commit is contained in:
Idan Horowitz 2021-04-15 19:22:02 +10:00 • committed by Andreas Kling
parent 42b1eb5af1
commit ecfa7cb824
8 changed files with 35 additions and 18 deletions
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20
Kernel/VirtIO/VirtIOConsole.cpp
View file

@ -61,9 +61,14 @@ VirtIOConsole::VirtIOConsole(PCI::Address address)
get_queue(RECEIVEQ).on_data_available = [&]() {
dbgln("VirtIOConsole: receive_queue on_data_available");
};
m_receive_region = MM.allocate_contiguous_kernel_region(PAGE_SIZE, "VirtIOConsole Receive", Region::Access::Read | Region::Access::Write);
if (m_receive_region) {
supply_buffer_and_notify(RECEIVEQ, m_receive_region->physical_page(0)->paddr().as_ptr(), m_receive_region->size(), BufferType::DeviceWritable);
}
get_queue(TRANSMITQ).on_data_available = [&]() {
dbgln("VirtIOConsole: send_queue on_data_available");
};
m_transmit_region = MM.allocate_contiguous_kernel_region(PAGE_SIZE, "VirtIOConsole Transmit", Region::Access::Read | Region::Access::Write);
dbgln("TODO: Populate receive queue with a receive buffer");
}
}
@ -101,17 +106,14 @@ KResultOr<size_t> VirtIOConsole::write(FileDescription&, u64, const UserOrKernel
{
if (!size)
return 0;
VERIFY(size <= PAGE_SIZE);
dbgln("VirtIOConsole: Write with size {}, kernel: {}", size, data.is_kernel_buffer());
if (!data.read(m_transmit_region->vaddr().as_ptr(), size)) {
return Kernel::KResult((ErrnoCode)-EFAULT);
}
supply_buffer_and_notify(TRANSMITQ, m_transmit_region->physical_page(0)->paddr().as_ptr(), size, BufferType::DeviceReadable);
ssize_t nread = data.read_buffered<256>(size, [&](const u8* bytes, size_t bytes_count) {
supply_buffer_and_notify(TRANSMITQ, bytes, bytes_count, BufferType::DeviceReadable);
return (ssize_t)bytes_count;
});
if (nread < 0)
return Kernel::KResult((ErrnoCode)-nread);
return (size_t)nread;
return size;
}
}