Fix to issues with kvm.h and g++

[Daniel Godás]

Hello,

I am writing a kvm-based emulation framework in c++. When I included
linux/kvm.h I got the following errors:

/usr/include/linux/kvm.h:89: error: 'struct kvm_run::anonymous
union::kvm_io' invalid; an anonymous union can only have non-static
data members
/usr/include/linux/kvm.h:230: error: declaration of '__u64
kvm_dirty_log::anonymous union::padding'
/usr/include/linux/kvm.h:227: error: conflicts with previous
declaration '__u32 kvm_dirty_log::padding'
/usr/include/linux/kvm.h:89: error: 'struct kvm_run::anonymous
union::kvm_io' invalid; an anonymous union can only have non-static
data members
/usr/include/linux/kvm.h:230: error: declaration of '__u64
kvm_dirty_log::anonymous union::padding'
/usr/include/linux/kvm.h:227: error: conflicts with previous
declaration '__u32 kvm_dirty_log::padding'

It looks like nobody uses struct kvm_io nor in kernel or user space.
The same happens with the two padding fields. The following patch
fixes the errors:

diff --git a/include/linux/kvm.h b/include/linux/kvm.h
index 44fd7fa..f357d50 100644
--- a/include/linux/kvm.h
+++ b/include/linux/kvm.h
@@ -119,7 +119,7 @@ struct kvm_run {
__u32 error_code;
} ex;
/* KVM_EXIT_IO */
-   struct kvm_io {
+   struct {
 #define KVM_EXIT_IO_IN  0
 #define KVM_EXIT_IO_OUT 1
__u8 direction;
@@ -238,10 +238,10 @@ struct kvm_debug_guest {
 /* for KVM_GET_DIRTY_LOG */
 struct kvm_dirty_log {
__u32 slot;
-   __u32 padding;
+   __u32 padding1;
union {
void __user *dirty_bitmap; /* one bit per page */
-   __u64 padding;
+   __u64 padding2;
};
 };


Cheers,
Daniel
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KVM_CAP_DEVICE_ASSIGNMENT should depend on CONFIG_PCI

[Daniel Godás]

Hello,

if you compile the kernel with KVM activated and without PCI support
you get the following crash:

  CC  arch/x86/kvm/../../../virt/kvm/kvm_main.o
arch/x86/kvm/../../../virt/kvm/kvm_main.c: In function
'kvm_free_assigned_device':
arch/x86/kvm/../../../virt/kvm/kvm_main.c:155: error: implicit
declaration of function 'pci_reset_function'
make[1]: *** [arch/x86/kvm/../../../virt/kvm/kvm_main.o] Error 1
make: *** [arch/x86/kvm] Error 2

This can be reproduced by using the attached config file. Obviously
the pci_reset_function should not be called when PCI support is
disabled. These changes fix the issue:

diff --git a/include/linux/kvm.h b/include/linux/kvm.h
index 44fd7fa..d93de2c 100644
--- a/include/linux/kvm.h
+++ b/include/linux/kvm.h
@@ -387,7 +387,7 @@ struct kvm_trace_rec {
 #define KVM_CAP_MP_STATE 14
 #define KVM_CAP_COALESCED_MMIO 15
 #define KVM_CAP_SYNC_MMU 16  /* Changes to host mmap are reflected in guest */
-#if defined(CONFIG_X86)||defined(CONFIG_IA64)
+#if (defined(CONFIG_X86)||defined(CONFIG_IA64))  defined(CONFIG_PCI)
 #define KVM_CAP_DEVICE_ASSIGNMENT 17
 #endif
 #define KVM_CAP_IOMMU 18

diff --git a/arch/x86/kvm/x86.c b/arch/x86/kvm/x86.c
index 9a4a39c..0397c65 100644
--- a/arch/x86/kvm/x86.c
+++ b/arch/x86/kvm/x86.c
@@ -4148,7 +4148,9 @@ static void kvm_free_vcpus(struct kvm *kvm)

 void kvm_arch_destroy_vm(struct kvm *kvm)
 {
+#ifdef KVM_CAP_DEVICE_ASSIGNMENT
kvm_free_all_assigned_devices(kvm);
+#endif
kvm_iommu_unmap_guest(kvm);
kvm_free_pit(kvm);
kfree(kvm-arch.vpic);

diff --git a/arch/x86/kernel/pci-dma.c b/arch/x86/kernel/pci-dma.c
index 1972266..47c5a7a 100644
--- a/arch/x86/kernel/pci-dma.c
+++ b/arch/x86/kernel/pci-dma.c
@@ -202,6 +202,7 @@ static __init int iommu_setup(char *p)
iommu_merge = 0;
if (!strncmp(p, forcesac, 8))
iommu_sac_force = 1;
+#ifdef CONFIG_PCI
if (!strncmp(p, allowdac, 8))
forbid_dac = 0;
if (!strncmp(p, nodac, 5))
@@ -210,6 +211,7 @@ static __init int iommu_setup(char *p)
forbid_dac = -1;
return 1;
}
+#endif
 #ifdef CONFIG_SWIOTLB
if (!strncmp(p, soft, 4))
swiotlb = 1;

Cheers,
Daniel


test_config
Description: Binary data


dep_pci.patch
Description: Binary data

Re: KVM-74 and network timeout?

[Daniel Godás]

Hi, ive been using a JetFlash usb-storage device with kvm-qemu and
Windows XP as a guest. I have seen that before setting up the device
properly, Windows resets it 5 or 6 times, which makes the process
awfully slow. Diving into the code I found that qemu's emulation was
not giving the host the right status when there was a babble or
stall situation. After applying the following patch the setup time
was cut up by a ~200%.

Cheers,
Daniel

--- old/kvm-75/qemu/usb-linux.c 2008-09-07 18:38:33.0 +0200
+++ new/kvm-75/qemu/usb-linux.c 2008-09-18 15:13:47.0 +0200
@@ -208,9 +208,13 @@
 p-len = aurb-urb.actual_length;
 break;

+case -EOVERFLOW:
+   p-len = USB_RET_BABBLE;
+   break;
 case -EPIPE:
 set_halt(s, p-devep);
-/* fall through */
+p-len = USB_RET_STALL;
+   break;
 default:
 p-len = USB_RET_NAK;
 break;


usb_fix.patch
Description: Binary data