qemu has the fw_cfg mechanism to pass data from the emulator to the bios.
SeaBIOS also includes fw_cfg support and so it makes sense to add this to
vmd(4) as well. To make this happen the following IO ports need to be
forwarded by vmm(4) to vmd(8).
FW_CFG_IO_SELECT 0x510
FW_CFG_IO_DATA 0x511
FW_CFG_IO_DMA_ADDR_HIGH 0x514
FW_CFG_IO_DMA_ADDR_LOW 0x518
It is possible to not use the DMA interface but I think it may be better
to have it.
--
:wq Claudio
Index: arch/amd64/amd64//vmm.c
===================================================================
RCS file: /cvs/src/sys/arch/amd64/amd64/vmm.c,v
retrieving revision 1.221
diff -u -p -r1.221 vmm.c
--- arch/amd64/amd64//vmm.c 7 Oct 2018 22:43:06 -0000 1.221
+++ arch/amd64/amd64//vmm.c 10 Dec 2018 14:46:52 -0000
@@ -5128,7 +5128,9 @@ svm_handle_inout(struct vcpu *vcpu)
case IO_ICU2 ... IO_ICU2 + 1:
case 0x3f8 ... 0x3ff:
case ELCR0 ... ELCR1:
- case 0x500 ... 0x50f:
+ case 0x500 ... 0x511:
+ case 0x514:
+ case 0x518:
case 0xcf8:
case 0xcfc ... 0xcff:
case VMM_PCI_IO_BAR_BASE ... VMM_PCI_IO_BAR_END:
@@ -5221,9 +5223,11 @@ vmx_handle_inout(struct vcpu *vcpu)
case IO_ICU2 ... IO_ICU2 + 1:
case 0x3f8 ... 0x3ff:
case ELCR0 ... ELCR1:
+ case 0x500 ... 0x511:
+ case 0x514:
+ case 0x518:
case 0xcf8:
case 0xcfc ... 0xcff:
- case 0x500 ... 0x50f:
case VMM_PCI_IO_BAR_BASE ... VMM_PCI_IO_BAR_END:
ret = EAGAIN;
break;
