On Fri, Feb 25, 2011 at 02:28:02PM +0800, Sheng Yang wrote:
> On Thursday 24 February 2011 18:45:08 Michael S. Tsirkin wrote:
> > On Thu, Feb 24, 2011 at 05:51:04PM +0800, Sheng Yang wrote:
> > > Then we can support mask bit operation of assigned devices now.
> > >
> > > Signed-off-by: Sheng Yang <sheng@xxxxxxxxxxxxxxx>
> >
> > Doesn't look like all comments got addressed.
> > E.g. gpa_t entry_base is still there and in reality
> > you said it's a host virtual address so
> > should be void __user *;
>
> Would update it.
>
> > And ENOTSYNC meaning 'MSIX' is pretty hacky.
>
> I'd like to discuss it later. We may need some work on all MMIO handling side to
> make it more straightforward. But I don't want to bundle it with this one...
It's not PCI related so I'll defer to Avi/Marcelo on this.
Are you guys happy with the ENOTSYNC meaning 'MSIX'
and userspace_exit_needed hacks in this code?
> >
> > > ---
> > >
> > > arch/x86/include/asm/kvm_host.h | 1 +
> > > arch/x86/kvm/Makefile | 2 +-
> > > arch/x86/kvm/mmu.c | 2 +
> > > arch/x86/kvm/x86.c | 40 ++++-
> > > include/linux/kvm.h | 28 ++++
> > > include/linux/kvm_host.h | 34 +++++
> > > virt/kvm/assigned-dev.c | 44 ++++++
> > > virt/kvm/kvm_main.c | 38 +++++-
> > > virt/kvm/msix_mmio.c | 296
> > > +++++++++++++++++++++++++++++++++++++++ virt/kvm/msix_mmio.h
> > > | 25 ++++
> > > 10 files changed, 497 insertions(+), 13 deletions(-)
> > > create mode 100644 virt/kvm/msix_mmio.c
> > > create mode 100644 virt/kvm/msix_mmio.h
> > >
> > > diff --git a/arch/x86/include/asm/kvm_host.h
> > > b/arch/x86/include/asm/kvm_host.h index aa75f21..4a390a4 100644
> > > --- a/arch/x86/include/asm/kvm_host.h
> > > +++ b/arch/x86/include/asm/kvm_host.h
> > > @@ -635,6 +635,7 @@ enum emulation_result {
> > >
> > > EMULATE_DONE, /* no further processing */
> > > EMULATE_DO_MMIO, /* kvm_run filled with mmio request */
> > > EMULATE_FAIL, /* can't emulate this instruction */
> > >
> > > + EMULATE_USERSPACE_EXIT, /* we need exit to userspace */
> > >
> > > };
> > >
> > > #define EMULTYPE_NO_DECODE (1 << 0)
> > >
> > > diff --git a/arch/x86/kvm/Makefile b/arch/x86/kvm/Makefile
> > > index f15501f..3a0d851 100644
> > > --- a/arch/x86/kvm/Makefile
> > > +++ b/arch/x86/kvm/Makefile
> > > @@ -7,7 +7,7 @@ CFLAGS_vmx.o := -I.
> > >
> > > kvm-y += $(addprefix ../../../virt/kvm/, kvm_main.o ioapic.o \
> > >
> > > coalesced_mmio.o irq_comm.o eventfd.o \
> > >
> > > - assigned-dev.o)
> > > + assigned-dev.o msix_mmio.o)
> > >
> > > kvm-$(CONFIG_IOMMU_API) += $(addprefix ../../../virt/kvm/, iommu.o)
> > > kvm-$(CONFIG_KVM_ASYNC_PF) += $(addprefix ../../../virt/kvm/,
> > > async_pf.o)
> > >
> > > diff --git a/arch/x86/kvm/mmu.c b/arch/x86/kvm/mmu.c
> > > index 9cafbb4..912dca4 100644
> > > --- a/arch/x86/kvm/mmu.c
> > > +++ b/arch/x86/kvm/mmu.c
> > > @@ -3358,6 +3358,8 @@ int kvm_mmu_page_fault(struct kvm_vcpu *vcpu, gva_t
> > > cr2, u32 error_code,
> > >
> > > case EMULATE_DO_MMIO:
> > > ++vcpu->stat.mmio_exits;
> > > /* fall through */
> > >
> > > + case EMULATE_USERSPACE_EXIT:
> > > + /* fall through */
> > >
> > > case EMULATE_FAIL:
> > > return 0;
> > >
> > > default:
> > > diff --git a/arch/x86/kvm/x86.c b/arch/x86/kvm/x86.c
> > > index 21b84e2..87308eb 100644
> > > --- a/arch/x86/kvm/x86.c
> > > +++ b/arch/x86/kvm/x86.c
> > > @@ -1966,6 +1966,7 @@ int kvm_dev_ioctl_check_extension(long ext)
> > >
> > > case KVM_CAP_X86_ROBUST_SINGLESTEP:
> > > case KVM_CAP_XSAVE:
> > >
> > > case KVM_CAP_ASYNC_PF:
> > > + case KVM_CAP_MSIX_MMIO:
> > > r = 1;
> > > break;
> > >
> > > case KVM_CAP_COALESCED_MMIO:
> > > @@ -3809,6 +3810,7 @@ static int emulator_write_emulated_onepage(unsigned
> > > long addr,
> > >
> > > {
> > >
> > > gpa_t gpa;
> > > struct kvm_io_ext_data ext_data;
> > >
> > > + int r;
> > >
> > > gpa = kvm_mmu_gva_to_gpa_write(vcpu, addr, exception);
> > >
> > > @@ -3824,18 +3826,32 @@ static int
> > > emulator_write_emulated_onepage(unsigned long addr,
> > >
> > > mmio:
> > > trace_kvm_mmio(KVM_TRACE_MMIO_WRITE, bytes, gpa, *(u64 *)val);
> > >
> > > + r = vcpu_mmio_write(vcpu, gpa, bytes, val, &ext_data);
> > >
> > > /*
> > >
> > > * Is this MMIO handled locally?
> > > */
> > >
> > > - if (!vcpu_mmio_write(vcpu, gpa, bytes, val, &ext_data))
> > > + if (!r)
> > >
> > > return X86EMUL_CONTINUE;
> > >
> > > - vcpu->mmio_needed = 1;
> > > - vcpu->run->exit_reason = KVM_EXIT_MMIO;
> > > - vcpu->run->mmio.phys_addr = vcpu->mmio_phys_addr = gpa;
> > > - vcpu->run->mmio.len = vcpu->mmio_size = bytes;
> > > - vcpu->run->mmio.is_write = vcpu->mmio_is_write = 1;
> > > - memcpy(vcpu->run->mmio.data, val, bytes);
> > > + if (r == -ENOTSYNC) {
> > > + vcpu->userspace_exit_needed = 1;
> > > + vcpu->run->exit_reason = KVM_EXIT_MSIX_ROUTING_UPDATE;
> > > + vcpu->run->msix_routing.dev_id =
> > > + ext_data.msix_routing.dev_id;
> > > + vcpu->run->msix_routing.type =
> > > + ext_data.msix_routing.type;
> > > + vcpu->run->msix_routing.entry_idx =
> > > + ext_data.msix_routing.entry_idx;
> > > + vcpu->run->msix_routing.flags =
> > > + ext_data.msix_routing.flags;
> > > + } else {
> > > + vcpu->mmio_needed = 1;
> > > + vcpu->run->exit_reason = KVM_EXIT_MMIO;
> > > + vcpu->run->mmio.phys_addr = vcpu->mmio_phys_addr = gpa;
> > > + vcpu->run->mmio.len = vcpu->mmio_size = bytes;
> > > + vcpu->run->mmio.is_write = vcpu->mmio_is_write = 1;
> > > + memcpy(vcpu->run->mmio.data, val, bytes);
> > > + }
> > >
> > > return X86EMUL_CONTINUE;
> > >
> > > }
> > >
> > > @@ -4469,6 +4485,8 @@ done:
> > > r = EMULATE_DO_MMIO;
> > >
> > > } else if (r == EMULATION_RESTART)
> > >
> > > goto restart;
> > >
> > > + else if (vcpu->userspace_exit_needed)
> > > + r = EMULATE_USERSPACE_EXIT;
> > >
> > > else
> > >
> > > r = EMULATE_DONE;
> > >
> > > @@ -5397,12 +5415,18 @@ int kvm_arch_vcpu_ioctl_run(struct kvm_vcpu
> > > *vcpu, struct kvm_run *kvm_run)
> > >
> > > }
> > >
> > > }
> > >
> > > - if (vcpu->arch.pio.count || vcpu->mmio_needed) {
> > > + if (vcpu->arch.pio.count || vcpu->mmio_needed ||
> > > + vcpu->userspace_exit_needed) {
> > >
> > > if (vcpu->mmio_needed) {
> > >
> > > memcpy(vcpu->mmio_data, kvm_run->mmio.data, 8);
> > > vcpu->mmio_read_completed = 1;
> > > vcpu->mmio_needed = 0;
> > >
> > > }
> > >
> > > + if (vcpu->userspace_exit_needed) {
> > > + vcpu->userspace_exit_needed = 0;
> > > + r = 0;
> > > + goto out;
> > > + }
> > >
> > > vcpu->srcu_idx = srcu_read_lock(&vcpu->kvm->srcu);
> > > r = emulate_instruction(vcpu, EMULTYPE_NO_DECODE);
> > > srcu_read_unlock(&vcpu->kvm->srcu, vcpu->srcu_idx);
> > >
> > > diff --git a/include/linux/kvm.h b/include/linux/kvm.h
> > > index ea2dc1a..4393e4e 100644
> > > --- a/include/linux/kvm.h
> > > +++ b/include/linux/kvm.h
> > > @@ -161,6 +161,7 @@ struct kvm_pit_config {
> > >
> > > #define KVM_EXIT_NMI 16
> > > #define KVM_EXIT_INTERNAL_ERROR 17
> > > #define KVM_EXIT_OSI 18
> > >
> > > +#define KVM_EXIT_MSIX_ROUTING_UPDATE 19
> > >
> > > /* For KVM_EXIT_INTERNAL_ERROR */
> > > #define KVM_INTERNAL_ERROR_EMULATION 1
> > >
> > > @@ -264,6 +265,13 @@ struct kvm_run {
> > >
> > > struct {
> > >
> > > __u64 gprs[32];
> > >
> > > } osi;
> > >
> > > + /* KVM_EXIT_MSIX_ROUTING_UPDATE*/
> > > + struct {
> > > + __u32 dev_id;
> > > + __u16 type;
> > > + __u16 entry_idx;
> > > + __u64 flags;
> > > + } msix_routing;
> > >
> > > /* Fix the size of the union. */
> > > char padding[256];
> > >
> > > };
> > >
> > > @@ -541,6 +549,7 @@ struct kvm_ppc_pvinfo {
> > >
> > > #define KVM_CAP_PPC_GET_PVINFO 57
> > > #define KVM_CAP_PPC_IRQ_LEVEL 58
> > > #define KVM_CAP_ASYNC_PF 59
> > >
> > > +#define KVM_CAP_MSIX_MMIO 60
> > >
> > > #ifdef KVM_CAP_IRQ_ROUTING
> > >
> > > @@ -672,6 +681,9 @@ struct kvm_clock_data {
> > >
> > > #define KVM_XEN_HVM_CONFIG _IOW(KVMIO, 0x7a, struct
> > > kvm_xen_hvm_config) #define KVM_SET_CLOCK _IOW(KVMIO,
> > > 0x7b, struct kvm_clock_data) #define KVM_GET_CLOCK
> > > _IOR(KVMIO, 0x7c, struct kvm_clock_data)
> > >
> > > +/* Available with KVM_CAP_MSIX_MMIO */
> > > +#define KVM_REGISTER_MSIX_MMIO _IOW(KVMIO, 0x7d, struct
> > > kvm_msix_mmio_user) +#define KVM_UNREGISTER_MSIX_MMIO _IOW(KVMIO,
> > > 0x7e, struct kvm_msix_mmio_user)
> > >
> > > /* Available with KVM_CAP_PIT_STATE2 */
> > > #define KVM_GET_PIT2 _IOR(KVMIO, 0x9f, struct
> > > kvm_pit_state2) #define KVM_SET_PIT2 _IOW(KVMIO, 0xa0,
> > > struct kvm_pit_state2)
> > >
> > > @@ -795,4 +807,20 @@ struct kvm_assigned_msix_entry {
> > >
> > > __u16 padding[3];
> > >
> > > };
> > >
> > > +#define KVM_MSIX_MMIO_TYPE_ASSIGNED_DEV (1 << 0)
> > > +
> > > +#define KVM_MSIX_MMIO_TYPE_BASE_TABLE (1 << 8)
> > > +
> > > +#define KVM_MSIX_MMIO_TYPE_DEV_MASK 0x00ff
> > > +#define KVM_MSIX_MMIO_TYPE_BASE_MASK 0xff00
> > > +struct kvm_msix_mmio_user {
> > > + __u32 dev_id;
> > > + __u16 type;
> > > + __u16 max_entries_nr;
> > > + __u64 base_addr;
> > > + __u64 base_va;
> > > + __u64 flags;
> > > + __u64 reserved[4];
> > > +};
> > > +
> > >
> > > #endif /* __LINUX_KVM_H */
> > >
> > > diff --git a/include/linux/kvm_host.h b/include/linux/kvm_host.h
> > > index 6bb211d..6aaf85e 100644
> > > --- a/include/linux/kvm_host.h
> > > +++ b/include/linux/kvm_host.h
> > > @@ -68,9 +68,16 @@ enum kvm_bus {
> > >
> > > KVM_NR_BUSES
> > >
> > > };
> > >
> > > +#define KVM_IO_EXT_DATA_TYPE_MSIX_ROUTING 1
> > >
> > > struct kvm_io_ext_data {
> > >
> > > int type;
> > > union {
> > >
> > > + struct {
> > > + u32 dev_id;
> > > + u16 type;
> > > + u16 entry_idx;
> > > + u64 flags;
Please, document the structure fields.
> > > + } msix_routing;
> > >
> > > char padding[256];
Note that there's another 2 bytes of padding before
the union as struct will be 8 byte aligned.
So if the purpose of the padding was to ensure
some fixed structure size, it failed in that.
> > >
> > > };
> > >
> > > };
> > >
> > > @@ -168,6 +175,8 @@ struct kvm_vcpu {
> > >
> > > } async_pf;
> > >
> > > #endif
> > >
> > > + int userspace_exit_needed;
> > > +
> > >
> > > struct kvm_vcpu_arch arch;
> > >
> > > };
> > >
> > > @@ -241,6 +250,27 @@ struct kvm_memslots {
> > >
> > > KVM_PRIVATE_MEM_SLOTS];
> > >
> > > };
> > >
> > > +#define KVM_MSIX_MMIO_MAX 32
> > > +
> > > +struct kvm_msix_mmio {
> > > + u32 dev_id;
> > > + u16 type;
> > > + u16 max_entries_nr;
> > > + u64 flags;
> > > + gpa_t table_base_addr;
> > > + hva_t table_base_va;
> > > + gpa_t pba_base_addr;
> > > + hva_t pba_base_va;
> > > +};
> > > +
> > > +struct kvm_msix_mmio_dev {
> > > + struct kvm *kvm;
> > > + struct kvm_io_device table_dev;
> > > + int mmio_nr;
> > > + struct kvm_msix_mmio mmio[KVM_MSIX_MMIO_MAX];
> > > + struct mutex lock;
> > > +};
> > > +
> > >
> > > struct kvm {
> > >
> > > spinlock_t mmu_lock;
> > > raw_spinlock_t requests_lock;
> > >
> > > @@ -289,6 +319,7 @@ struct kvm {
> > >
> > > long mmu_notifier_count;
> > >
> > > #endif
> > >
> > > long tlbs_dirty;
> > >
> > > + struct kvm_msix_mmio_dev msix_mmio_dev;
> > >
> > > };
> > >
> > > /* The guest did something we don't support. */
> > >
> > > @@ -561,6 +592,9 @@ void kvm_unregister_irq_ack_notifier(struct kvm *kvm,
> > >
> > > int kvm_request_irq_source_id(struct kvm *kvm);
> > > void kvm_free_irq_source_id(struct kvm *kvm, int irq_source_id);
> > >
> > > +int kvm_assigned_device_update_msix_mask_bit(struct kvm *kvm,
> > > + int assigned_dev_id, int entry, bool mask);
> > > +
> > >
> > > /* For vcpu->arch.iommu_flags */
> > > #define KVM_IOMMU_CACHE_COHERENCY 0x1
> > >
> > > diff --git a/virt/kvm/assigned-dev.c b/virt/kvm/assigned-dev.c
> > > index ae72ae6..d1598a6 100644
> > > --- a/virt/kvm/assigned-dev.c
> > > +++ b/virt/kvm/assigned-dev.c
> > > @@ -18,6 +18,7 @@
> > >
> > > #include <linux/interrupt.h>
> > > #include <linux/slab.h>
> > > #include "irq.h"
> > >
> > > +#include "msix_mmio.h"
> > >
> > > static struct kvm_assigned_dev_kernel *kvm_find_assigned_dev(struct
> > > list_head *head,
> > >
> > > int assigned_dev_id)
> > >
> > > @@ -191,12 +192,25 @@ static void kvm_free_assigned_irq(struct kvm *kvm,
> > >
> > > kvm_deassign_irq(kvm, assigned_dev, assigned_dev->irq_requested_type);
> > >
> > > }
> > >
> > > +static void assigned_device_free_msix_mmio(struct kvm *kvm,
> > > + struct kvm_assigned_dev_kernel *adev)
> > > +{
> > > + struct kvm_msix_mmio mmio;
> > > +
> > > + mmio.dev_id = adev->assigned_dev_id;
> > > + mmio.type = KVM_MSIX_MMIO_TYPE_ASSIGNED_DEV |
> > > + KVM_MSIX_MMIO_TYPE_BASE_TABLE;
> > > + kvm_free_msix_mmio(kvm, &mmio);
> > > +}
> > > +
> > >
> > > static void kvm_free_assigned_device(struct kvm *kvm,
> > >
> > > struct kvm_assigned_dev_kernel
> > > *assigned_dev)
> > >
> > > {
> > >
> > > kvm_free_assigned_irq(kvm, assigned_dev);
> > >
> > > + assigned_device_free_msix_mmio(kvm, assigned_dev);
> > > +
> > >
> > > __pci_reset_function(assigned_dev->dev);
> > > pci_restore_state(assigned_dev->dev);
> > >
> > > @@ -785,3 +799,33 @@ out:
> > > return r;
> > >
> > > }
> > >
> > > +/* The caller should hold kvm->lock */
> > > +int kvm_assigned_device_update_msix_mask_bit(struct kvm *kvm,
> > > + int assigned_dev_id, int entry, bool mask)
> > > +{
> > > + int r = -EFAULT;
> > > + struct kvm_assigned_dev_kernel *adev;
> > > + int i;
> > > +
> > > + if (!irqchip_in_kernel(kvm))
> > > + return r;
> > > +
> > > + adev = kvm_find_assigned_dev(&kvm->arch.assigned_dev_head,
> > > + assigned_dev_id);
> > > + if (!adev)
> > > + goto out;
> > > +
> > > + /* For non-MSIX enabled devices, entries_nr == 0 */
> > > + for (i = 0; i < adev->entries_nr; i++)
> > > + if (adev->host_msix_entries[i].entry == entry) {
> > > + if (mask)
> > > + disable_irq_nosync(
> > > + adev->host_msix_entries[i].vector);
> > > + else
> > > + enable_irq(adev->host_msix_entries[i].vector);
> > > + r = 0;
> > > + break;
> > > + }
> > > +out:
> > > + return r;
> > > +}
> > > diff --git a/virt/kvm/kvm_main.c b/virt/kvm/kvm_main.c
> > > index a61f90e..f211e49 100644
> > > --- a/virt/kvm/kvm_main.c
> > > +++ b/virt/kvm/kvm_main.c
> > > @@ -56,6 +56,7 @@
> > >
> > > #include "coalesced_mmio.h"
> > > #include "async_pf.h"
> > >
> > > +#include "msix_mmio.h"
> > >
> > > #define CREATE_TRACE_POINTS
> > > #include <trace/events/kvm.h>
> > >
> > > @@ -509,6 +510,7 @@ static void kvm_destroy_vm(struct kvm *kvm)
> > >
> > > struct mm_struct *mm = kvm->mm;
> > >
> > > kvm_arch_sync_events(kvm);
> > >
> > > + kvm_unregister_msix_mmio_dev(kvm);
> > >
> > > spin_lock(&kvm_lock);
> > > list_del(&kvm->vm_list);
> > > spin_unlock(&kvm_lock);
> > >
> > > @@ -1877,6 +1879,24 @@ static long kvm_vm_ioctl(struct file *filp,
> > >
> > > mutex_unlock(&kvm->lock);
> > > break;
> > >
> > > #endif
> > >
> > > + case KVM_REGISTER_MSIX_MMIO: {
> > > + struct kvm_msix_mmio_user mmio_user;
> > > +
> > > + r = -EFAULT;
> > > + if (copy_from_user(&mmio_user, argp, sizeof mmio_user))
> > > + goto out;
> > > + r = kvm_vm_ioctl_register_msix_mmio(kvm, &mmio_user);
> > > + break;
> > > + }
> > > + case KVM_UNREGISTER_MSIX_MMIO: {
> > > + struct kvm_msix_mmio_user mmio_user;
> > > +
> > > + r = -EFAULT;
> > > + if (copy_from_user(&mmio_user, argp, sizeof mmio_user))
> > > + goto out;
> > > + r = kvm_vm_ioctl_unregister_msix_mmio(kvm, &mmio_user);
> > > + break;
> > > + }
> > >
> > > default:
> > > r = kvm_arch_vm_ioctl(filp, ioctl, arg);
> > > if (r == -ENOTTY)
> > >
> > > @@ -1988,6 +2008,12 @@ static int kvm_dev_ioctl_create_vm(void)
> > >
> > > return r;
> > >
> > > }
> > >
> > > #endif
> > >
> > > + r = kvm_register_msix_mmio_dev(kvm);
> > > + if (r < 0) {
> > > + kvm_put_kvm(kvm);
> > > + return r;
> > > + }
> > > +
> > >
> > > r = anon_inode_getfd("kvm-vm", &kvm_vm_fops, kvm, O_RDWR);
> > > if (r < 0)
> > >
> > > kvm_put_kvm(kvm);
> > >
> > > @@ -2223,14 +2249,18 @@ static void kvm_io_bus_destroy(struct kvm_io_bus
> > > *bus)
> > >
> > > int kvm_io_bus_write(struct kvm *kvm, enum kvm_bus bus_idx, gpa_t addr,
> > >
> > > int len, const void *val, struct kvm_io_ext_data *ext_data)
> > >
> > > {
> > >
> > > - int i;
> > > + int i, r = -EOPNOTSUPP;
> > >
> > > struct kvm_io_bus *bus;
> > >
> > > bus = srcu_dereference(kvm->buses[bus_idx], &kvm->srcu);
> > >
> > > - for (i = 0; i < bus->dev_count; i++)
> > > - if (!kvm_iodevice_write(bus->devs[i], addr, len, val, ext_data))
> > > + for (i = 0; i < bus->dev_count; i++) {
> > > + r = kvm_iodevice_write(bus->devs[i], addr, len, val, ext_data);
> > > + if (r == -ENOTSYNC)
> > > + break;
> > > + else if (!r)
> > >
> > > return 0;
> > >
> > > - return -EOPNOTSUPP;
> > > + }
> > > + return r;
> > >
> > > }
> > >
> > > /* kvm_io_bus_read - called under kvm->slots_lock */
> > >
> > > diff --git a/virt/kvm/msix_mmio.c b/virt/kvm/msix_mmio.c
> > > new file mode 100644
> > > index 0000000..083b15b
> > > --- /dev/null
> > > +++ b/virt/kvm/msix_mmio.c
> > > @@ -0,0 +1,296 @@
> > > +/*
> > > + * MSI-X MMIO emulation
> > > + *
> > > + * Copyright (c) 2010 Intel Corporation
> > > + *
> > > + * This work is licensed under the terms of the GNU GPL, version 2. See
> > > + * the COPYING file in the top-level directory.
> > > + *
> > > + * Author:
> > > + * Sheng Yang <sheng.yang@xxxxxxxxx>
> > > + */
> > > +
> > > +#include <linux/kvm_host.h>
> > > +#include <linux/kvm.h>
> > > +
> > > +#include "msix_mmio.h"
> > > +#include "iodev.h"
> > > +
> > > +static int update_msix_mask_bit(struct kvm *kvm, struct kvm_msix_mmio
> > > *mmio, + int entry, u32 flag)
> > > +{
> > > + if (mmio->type & KVM_MSIX_MMIO_TYPE_ASSIGNED_DEV)
> > > + return kvm_assigned_device_update_msix_mask_bit(kvm,
> > > + mmio->dev_id, entry, flag);
> > > + return -EFAULT;
> > > +}
> > > +
> > > +/* Caller must hold dev->lock */
> > > +static int get_mmio_table_index(struct kvm_msix_mmio_dev *dev,
> > > + gpa_t addr, int len)
> > > +{
> > > + gpa_t start, end;
> > > + int i, r = -EINVAL;
> > > +
> > > + for (i = 0; i < dev->mmio_nr; i++) {
> > > + start = dev->mmio[i].table_base_addr;
> > > + end = dev->mmio[i].table_base_addr + PCI_MSIX_ENTRY_SIZE *
> > > + dev->mmio[i].max_entries_nr;
> > > + if (addr >= start && addr + len <= end) {
> > > + r = i;
> > > + break;
> > > + }
> > > + }
> > > +
> > > + return r;
> > > +}
> > > +
> > > +static int msix_table_mmio_read(struct kvm_io_device *this, gpa_t addr,
> > > int len, + void *val)
> > > +{
> > > + /*TODO: Add big endian support */
> > > + struct kvm_msix_mmio_dev *mmio_dev =
> > > + container_of(this, struct kvm_msix_mmio_dev, table_dev);
> > > + struct kvm_msix_mmio *mmio;
> > > + int idx, ret = 0, entry, offset, r;
> > > +
> > > + mutex_lock(&mmio_dev->lock);
> > > + idx = get_mmio_table_index(mmio_dev, addr, len);
> > > + if (idx < 0) {
> > > + ret = -EOPNOTSUPP;
> > > + goto out;
> > > + }
> > > + if ((addr & 0x3) || (len != 4 && len != 8))
> > > + goto out;
> >
> > addr & len as below?
> >
> > > +
> > > + offset = addr % PCI_MSIX_ENTRY_SIZE;
> > > + if (offset == PCI_MSIX_ENTRY_VECTOR_CTRL && len == 8)
> > > + goto out;
> >
> > then this test won't be needed.
> >
> > > +
> > > + mmio = &mmio_dev->mmio[idx];
> > > + entry = (addr - mmio->table_base_addr) / PCI_MSIX_ENTRY_SIZE;
> > > + r = copy_from_user(val, (void __user *)(mmio->table_base_va +
> > > + entry * PCI_MSIX_ENTRY_SIZE + offset), len);
> > > + if (r)
> > > + goto out;
> > > +out:
> > > + mutex_unlock(&mmio_dev->lock);
> > > + return ret;
> > > +}
> > > +
> > > +static int msix_table_mmio_write(struct kvm_io_device *this, gpa_t addr,
> > > + int len, const void *val,
> > > + struct kvm_io_ext_data *ext_data)
> > > +{
> > > + /*TODO: Add big endian support */
> > > + struct kvm_msix_mmio_dev *mmio_dev =
> > > + container_of(this, struct kvm_msix_mmio_dev, table_dev);
> > > + struct kvm_msix_mmio *mmio;
> > > + int idx, entry, offset, ret = 0, r = 0;
> > > + gpa_t entry_base;
> > > + u32 old_ctrl, new_ctrl;
> > > + unsigned long __user *ctrl_pos;
> >
> > long? It's 8 bytes on 64 bit.
> > You really want
> > __le32 old_ctrl, new_ctrl;
> > __le32 __user *ctrl_pos;
>
> __le32 here may cause wrong idea that we support big endian, but it's not true. So
> I want to use u32 here, and add TODO above.
Users don't go looking for __le32 in code. If you want to make sure
code is built on intel only, just check the architecture.
But understanding endianness and making the code correct
upfront is not hard, I really don't understand why
do you keep hardcoding LE assumptions in there,
__le32 is simply better, it let us know that the value
is related to pci as opposed to a random integer value.
> >
> > > +
> > > + mutex_lock(&mmio_dev->kvm->lock);
> > > + mutex_lock(&mmio_dev->lock);
> > > + idx = get_mmio_table_index(mmio_dev, addr, len);
> > > + if (idx < 0) {
> > > + ret = -EOPNOTSUPP;
> > > + goto out;
> > > + }
> > > + if (!(len == 4 || len == 8) || addr & (len - 1))
> >
> > Nice hack. Even a bit nicer
>
> Thanks Alex for this line. :)
>
> > if ((len != 4 && len != 8) || addr & (len - 1))
>
> I think it's personal style difference. These two look same to me...
One character less :) And you use != above. Be consistent or better
add an inline to avoid duplication.
> >
> > > + goto out;
> > > +
> > > + offset = addr % PCI_MSIX_ENTRY_SIZE;
> > > +
> > > + mmio = &mmio_dev->mmio[idx];
> > > + entry = (addr - mmio->table_base_addr) / PCI_MSIX_ENTRY_SIZE;
> > > + entry_base = mmio->table_base_va + entry * PCI_MSIX_ENTRY_SIZE;
> > > + ctrl_pos = (unsigned long __user *)(entry_base +
> > > + PCI_MSIX_ENTRY_VECTOR_CTRL);
> >
> > So this is the issue: if you cast a type to unsigned long *
> > compiler can assume that the address is aligned.
> > To prevent problems please add a check that table_base_va
> > is aligned.
>
> Already checked it when mmio register.
Right, missed it the first time around.
> >
> > > +
> > > + if (get_user(old_ctrl, ctrl_pos))
> > > + goto out;
> > > +
> > > + /* Don't allow writing to other fields when entry is unmasked */
> > > + if (!(old_ctrl & PCI_MSIX_ENTRY_CTRL_MASKBIT) &&
> > > + offset != PCI_MSIX_ENTRY_VECTOR_CTRL)
> > > + goto out;
> > > +
> > > + if (copy_to_user((void __user *)(entry_base + offset), val, len))
> > > + goto out;
> > > +
> > > + ext_data->type = KVM_IO_EXT_DATA_TYPE_MSIX_ROUTING;
> > > + ext_data->msix_routing.dev_id = mmio->dev_id;
> > > + ext_data->msix_routing.type = mmio->type;
> > > + ext_data->msix_routing.entry_idx = entry;
> > > + ext_data->msix_routing.flags = 0;
> > > +
> > > + if (offset + len < PCI_MSIX_ENTRY_VECTOR_CTRL) {
> > > + ret = -ENOTSYNC;
> > > + goto out;
> > > + }
> > > +
> > > + if (get_user(new_ctrl, ctrl_pos))
> > > + goto out;
> > > +
> > > + if (old_ctrl == new_ctrl) {
> > > + if (offset == PCI_MSIX_ENTRY_DATA && len == 8)
> > > + ret = -ENOTSYNC;
> > > + goto out;
> > > + }
> > > + if ((old_ctrl & PCI_MSIX_ENTRY_CTRL_MASKBIT) ^
> > > + (new_ctrl & PCI_MSIX_ENTRY_CTRL_MASKBIT))
> > > + r = update_msix_mask_bit(mmio_dev->kvm, mmio, entry,
> > > + !!(new_ctrl & PCI_MSIX_ENTRY_CTRL_MASKBIT));
> > > + if (r)
> > > + ret = -ENOTSYNC;
> > > +out:
> > > + mutex_unlock(&mmio_dev->lock);
> > > + mutex_unlock(&mmio_dev->kvm->lock);
> > > + return ret;
> > > +}
> > > +
> > > +static const struct kvm_io_device_ops msix_mmio_table_ops = {
> > > + .read = msix_table_mmio_read,
> > > + .write = msix_table_mmio_write,
> > > +};
> > > +
> > > +int kvm_register_msix_mmio_dev(struct kvm *kvm)
> > > +{
> > > + int ret;
> > > +
> > > + kvm_iodevice_init(&kvm->msix_mmio_dev.table_dev, &msix_mmio_table_ops);
> > > + mutex_init(&kvm->msix_mmio_dev.lock);
> > > + kvm->msix_mmio_dev.kvm = kvm;
> > > + mutex_lock(&kvm->slots_lock);
> > > + ret = kvm_io_bus_register_dev(kvm, KVM_MMIO_BUS,
> > > + &kvm->msix_mmio_dev.table_dev);
> > > + mutex_unlock(&kvm->slots_lock);
> > > + return ret;
> > > +}
> > > +
> > > +int kvm_unregister_msix_mmio_dev(struct kvm *kvm)
> > > +{
> > > + int ret;
> > > +
> > > + mutex_lock(&kvm->slots_lock);
> > > + ret = kvm_io_bus_unregister_dev(kvm, KVM_MMIO_BUS,
> > > + &kvm->msix_mmio_dev.table_dev);
> > > + mutex_unlock(&kvm->slots_lock);
> > > + return ret;
> > > +}
> > > +
> > > +int kvm_vm_ioctl_register_msix_mmio(struct kvm *kvm,
> > > + struct kvm_msix_mmio_user *mmio_user)
> > > +{
> > > + struct kvm_msix_mmio_dev *mmio_dev = &kvm->msix_mmio_dev;
> > > + struct kvm_msix_mmio *mmio = NULL;
> > > + int r = 0, i;
> > > +
> > > + mutex_lock(&mmio_dev->lock);
> > > + for (i = 0; i < mmio_dev->mmio_nr; i++) {
> > > + if (mmio_dev->mmio[i].dev_id == mmio_user->dev_id &&
> > > + (mmio_dev->mmio[i].type & KVM_MSIX_MMIO_TYPE_DEV_MASK) ==
> > > + (mmio_user->type & KVM_MSIX_MMIO_TYPE_DEV_MASK)) {
> > > + mmio = &mmio_dev->mmio[i];
> > > + if (mmio->max_entries_nr != mmio_user->max_entries_nr) {
> > > + r = -EINVAL;
> > > + goto out;
> > > + }
> > > + break;
> > > + }
> > > + }
> > > + if (mmio_user->max_entries_nr > KVM_MAX_MSIX_PER_DEV) {
> > > + r = -EINVAL;
> > > + goto out;
> > > + }
> > > + /* All reserved currently */
> > > + if (mmio_user->flags) {
> > > + r = -EINVAL;
> > > + goto out;
> > > + }
> > > +
> > > + if ((mmio_user->type & KVM_MSIX_MMIO_TYPE_DEV_MASK) !=
> > > + KVM_MSIX_MMIO_TYPE_ASSIGNED_DEV) {
> > > + r = -EINVAL;
> > > + goto out;
> > > + }
> > > + if ((mmio_user->type & KVM_MSIX_MMIO_TYPE_BASE_MASK) !=
> > > + KVM_MSIX_MMIO_TYPE_BASE_TABLE) {
> > > + r = -EINVAL;
> > > + goto out;
> > > + }
> > > +
> > > + /* Check alignment and accessibility */
> > > + if ((mmio_user->base_va % PCI_MSIX_ENTRY_SIZE) ||
> > > + !access_ok(VERIFY_WRITE, (void __user *)mmio_user->base_va,
> >
> > You also should check that base_va and friends fit in a pointer
> > for 32 bit architectures. Same for other va values.
>
> OK
>
> --
> regards
> Yang, Sheng
>
> >
> > > + mmio_user->max_entries_nr * PCI_MSIX_ENTRY_SIZE)) {
> > > + r = -EINVAL;
> > > + goto out;
> > > + }
> > > + if (!mmio) {
> > > + if (mmio_dev->mmio_nr == KVM_MSIX_MMIO_MAX) {
> > > + r = -ENOSPC;
> > > + goto out;
> > > + }
> > > + mmio = &mmio_dev->mmio[mmio_dev->mmio_nr];
> > > + mmio_dev->mmio_nr++;
> > > + }
> > > +
> > > + mmio->max_entries_nr = mmio_user->max_entries_nr;
> > > + mmio->dev_id = mmio_user->dev_id;
> > > + mmio->flags = mmio_user->flags;
> > > +
> > > + if ((mmio_user->type & KVM_MSIX_MMIO_TYPE_DEV_MASK) ==
> > > + KVM_MSIX_MMIO_TYPE_ASSIGNED_DEV)
> > > + mmio->type = KVM_MSIX_MMIO_TYPE_ASSIGNED_DEV;
> > > + if ((mmio_user->type & KVM_MSIX_MMIO_TYPE_BASE_MASK) ==
> > > + KVM_MSIX_MMIO_TYPE_BASE_TABLE) {
> > > + mmio->type |= KVM_MSIX_MMIO_TYPE_BASE_TABLE;
> > > + mmio->table_base_addr = mmio_user->base_addr;
> > > + mmio->table_base_va = mmio_user->base_va;
> > > + }
> > > +out:
> > > + mutex_unlock(&mmio_dev->lock);
> > > + return r;
> > > +}
> > > +
> > > +int kvm_free_msix_mmio(struct kvm *kvm, struct kvm_msix_mmio *mmio)
> > > +{
> > > + struct kvm_msix_mmio_dev *mmio_dev = &kvm->msix_mmio_dev;
> > > + int r = -EINVAL, i, j;
> > > +
> > > + if (!mmio)
> > > + return 0;
> > > +
> > > + mutex_lock(&mmio_dev->lock);
> > > + BUG_ON(mmio_dev->mmio_nr > KVM_MSIX_MMIO_MAX);
> > > + for (i = 0; i < mmio_dev->mmio_nr; i++) {
> > > + if (mmio_dev->mmio[i].dev_id == mmio->dev_id &&
> > > + mmio_dev->mmio[i].type == mmio->type) {
> > > + r = 0;
> > > + for (j = i; j < mmio_dev->mmio_nr - 1; j++)
> > > + mmio_dev->mmio[j] = mmio_dev->mmio[j + 1];
> > > + mmio_dev->mmio[mmio_dev->mmio_nr].max_entries_nr = 0;
> > > + mmio_dev->mmio[mmio_dev->mmio_nr].dev_id = 0;
> > > + mmio_dev->mmio[mmio_dev->mmio_nr].type = 0;
> > > + mmio_dev->mmio_nr--;
> > > + break;
> > > + }
> > > + }
> > > + mutex_unlock(&mmio_dev->lock);
> > > + return r;
> > > +}
> > > +
> > > +int kvm_vm_ioctl_unregister_msix_mmio(struct kvm *kvm,
> > > + struct kvm_msix_mmio_user *mmio_user)
> > > +{
> > > + struct kvm_msix_mmio mmio;
> > > +
> > > + mmio.dev_id = mmio_user->dev_id;
> > > + mmio.type = mmio_user->type;
> > > +
> > > + return kvm_free_msix_mmio(kvm, &mmio);
> > > +}
> > > +
> > > diff --git a/virt/kvm/msix_mmio.h b/virt/kvm/msix_mmio.h
> > > new file mode 100644
> > > index 0000000..01b6587
> > > --- /dev/null
> > > +++ b/virt/kvm/msix_mmio.h
> > > @@ -0,0 +1,25 @@
> > > +#ifndef __KVM_MSIX_MMIO_H__
> > > +#define __KVM_MSIX_MMIO_H__
> > > +/*
> > > + * MSI-X MMIO emulation
> > > + *
> > > + * Copyright (c) 2010 Intel Corporation
> > > + *
> > > + * This work is licensed under the terms of the GNU GPL, version 2. See
> > > + * the COPYING file in the top-level directory.
> > > + *
> > > + * Author:
> > > + * Sheng Yang <sheng.yang@xxxxxxxxx>
> > > + */
> > > +
> > > +#include <linux/pci.h>
> > > +
> > > +int kvm_register_msix_mmio_dev(struct kvm *kvm);
> > > +int kvm_unregister_msix_mmio_dev(struct kvm *kvm);
> > > +int kvm_vm_ioctl_register_msix_mmio(struct kvm *kvm,
> > > + struct kvm_msix_mmio_user *mmio_user);
> > > +int kvm_vm_ioctl_unregister_msix_mmio(struct kvm *kvm,
> > > + struct kvm_msix_mmio_user *mmio_user);
> > > +int kvm_free_msix_mmio(struct kvm *kvm, struct kvm_msix_mmio
> > > *mmio_user); +
> > > +#endif
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