virtio-net fixes

src/drivers/net/virtio-net.asm

@@ -271,6 +271,7 @@ virtio_net_init_reset_wait:
 	mov eax, [rsi+VIRTIO_DEVICE_FEATURE]
 	mov eax, 1
 	mov [rsi+VIRTIO_DRIVER_FEATURE_SELECT], eax
+	; TODO - Check into how LEGACY affects the 12-byte header
 	mov eax, 1			; Feature bits 63:32 - LEGACY (32)
 	mov [rsi+VIRTIO_DRIVER_FEATURE], eax
 
@@ -297,18 +298,19 @@ virtio_net_init_reset_wait:
 	xor eax, eax
 	mov [rsi+VIRTIO_QUEUE_SELECT], ax
 	mov ax, [rsi+VIRTIO_QUEUE_SIZE]	; Return the size of the queue
-	mov ecx, eax			; Store queue size in ECX
-	mov rax, [r8+nt_rx_desc]
+	mov [r8+0x7E], ax		; Store receive queue size in net_table
+	mov ecx, eax			; Store receive queue size in ECX
+	mov rax, [r8+nt_rx_desc]	; Set address of Descriptor ring
 	mov [rsi+VIRTIO_QUEUE_DESC], eax
 	rol rax, 32
 	mov [rsi+VIRTIO_QUEUE_DESC+8], eax
 	rol rax, 32
-	add rax, 4096
+	add rax, 4096			; Set address of Available ring
 	mov [rsi+VIRTIO_QUEUE_DRIVER], eax
 	rol rax, 32
 	mov [rsi+VIRTIO_QUEUE_DRIVER+8], eax
 	rol rax, 32
-	add rax, 4096
+	add rax, 4096			; Set address of Used ring
 	mov [rsi+VIRTIO_QUEUE_DEVICE], eax
 	rol rax, 32
 	mov [rsi+VIRTIO_QUEUE_DEVICE+8], eax
@@ -323,18 +325,19 @@ virtio_net_init_reset_wait:
 	mov eax, 1
 	mov [rsi+VIRTIO_QUEUE_SELECT], ax
 	mov ax, [rsi+VIRTIO_QUEUE_SIZE]	; Return the size of the queue
-	mov ecx, eax			; Store queue size in ECX
-	mov rax, [r8+nt_tx_desc]
+	mov [r8+0x7C], ax		; Store transmit queue size in net_table
+	mov ecx, eax			; Store transmit queue size in ECX
+	mov rax, [r8+nt_tx_desc]	; Set address of Descriptor ring
 	mov [rsi+VIRTIO_QUEUE_DESC], eax
 	rol rax, 32
 	mov [rsi+VIRTIO_QUEUE_DESC+8], eax
 	rol rax, 32
-	add rax, 4096
+	add rax, 4096			; Set address of Available ring
 	mov [rsi+VIRTIO_QUEUE_DRIVER], eax
 	rol rax, 32
 	mov [rsi+VIRTIO_QUEUE_DRIVER+8], eax
 	rol rax, 32
-	add rax, 4096
+	add rax, 4096			; Set address of Used ring
 	mov [rsi+VIRTIO_QUEUE_DEVICE], eax
 	rol rax, 32
 	mov [rsi+VIRTIO_QUEUE_DEVICE+8], eax
@@ -356,10 +359,12 @@ virtio_net_init_pop_tx_d:
 	; Populate RX Descriptor Table Entries
 	xor ecx, ecx
 	mov rdi, [r8+nt_rx_desc]
+	mov rbx, [os_PacketBase]
 virtio_net_init_pop_rx_d:
-	mov rax, os_PacketBuffers	; 64-bit Address
+	mov rax, rbx			; 64-bit Address
+	add rbx, 2048
 	stosq
-	mov eax, 1536			; 32-bit Length
+	mov eax, 2048			; 32-bit Length
 	stosd
 	mov ax, VIRTQ_DESC_F_WRITE
 	stosw				; 16-bit Flags
@@ -368,13 +373,15 @@ virtio_net_init_pop_rx_d:
 	stosw				; 16-bit Next
 	cmp cl, 0
 	jne virtio_net_init_pop_rx_d
+	mov [os_PacketBase], rbx
 
 	; Populate RX Available Ring Entries
 	mov rdi, [r8+nt_rx_desc]
 	add rdi, 0x1000
 	xor eax, eax
 	stosw				; 16-bit flags
-	mov ax, 128
+	mov ax, [r8+0x7C]		; Gather queue size
+	dec ax				; Mark all descriptors (minus 1) as available
 	stosw				; 16-bit index
 	xor eax, eax
 virtio_net_init_pop_rx_a:
@@ -509,31 +516,35 @@ net_virtio_transmit_wait:
 net_virtio_poll:
 	push r8
 	push rsi
+	push rbx
 	push rax
 
+	; Gather info from driver info
 	mov r8, [rdx+nt_rx_desc]
+	mov bx, [rdx+0x7E]		; Receive queue size
+	dec bx				; Ex: 0x100 becomes 0xFF
 
 	; Check if the Used Ring Index has changed from the last known value
 	mov rdi, r8
 	add rdi, 0x2000			; Offset to Used Ring
 	xor eax, eax
 	mov ax, [rdi+2]			; Load Used Ring Index
+	and ax, bx
 	cmp ax, [rdx+0x78]		; Check against the last known index value
 	je net_virtio_poll_nodata	; If equal then bail out
 
 	; Get size of packet that was received
-	mov ax, [rdx+0x78]		; Last known index
+	mov ax, [rdx+0x78]		; Get last known Used Ring Index
 	shl eax, 3			; Quick multiply by 8
-	add eax, 4			; Add offset to entries
+	add eax, 4			; Add offset to entries (skip 16-bit Flags and 16-bit Index)
 	add rdi, rax			; RDI points to the Used Ring Entry
-	mov rcx, [rdi]			; Load the 32-bit Index and 32-bit Length
+	mov rcx, [rdi]			; Load the 32-bit ID (low bits) and 32-bit Length (high bits) together
 
 	; Populate RX Available Ring
 	mov rdi, r8
 	add rdi, 0x1002			; Add offset to the Available Ring
 	mov ax, [rdi]			; 16-bit Index
-	inc ax
-	and ax, 0x00FF			; Wrap back to 0 if greater than 255
+	inc ax				; 65535 will wrap back around to 0
 	mov [rdi], ax			; 16-bit Index
 
 	; Set RDI to address of packet
@@ -552,12 +563,12 @@ net_virtio_poll:
 	; Increment internal counters
 	mov ax, [rdx+0x78]		; lastrx
 	inc ax
-	and ax, 0x00FF			; Wrap back to 0 if greater than 255
+	and ax, bx			; Wrap back to 0 if greater than queue length
 	mov [rdx+0x78], ax		; lastrx
-	mov [r8+0x2002], ax		; Store the new Used Ring Index
 
 net_virtio_poll_nodata:
 	pop rax
+	pop rbx
 	pop rsi
 	pop r8
 	ret

src/init/64.asm

@@ -108,6 +108,10 @@ make_interrupt_gate_stubs:
 	mov rax, 0x200000		; Stacks start at 2MiB
 	mov [os_StackBase], rax
 
+	; Configure Network packet buffer base
+	mov eax, 0x300000
+	mov [os_PacketBase], rax
+
 	; Configure the serial port (if present)
 	call serial_init
 

src/sysvar.asm

@@ -73,6 +73,7 @@ os_LocalAPICAddress:	equ os_SystemVariables + 0x0000
 os_IOAPICAddress:	equ os_SystemVariables + 0x0008
 os_SysConfEn:		equ os_SystemVariables + 0x0010	; Enabled bits: 0=PS/2 Keyboard, 1=PS/2 Mouse, 2=Serial, 4=HPET, 5=xHCI
 os_StackBase:		equ os_SystemVariables + 0x0020
+os_PacketBase:		equ os_SystemVariables + 0x0028
 sys_timer:		equ os_SystemVariables + 0x0048
 os_HPET_Address:	equ os_SystemVariables + 0x0050
 os_AHCI_Base:		equ os_SystemVariables + 0x0058