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vfio: pci: Allow multiple devices to be passed through

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The KVM_SET_GSI_ROUTING ioctl is very simple, it overrides the previous
routes configuration with the new ones being applied. This means the
caller, in this case cloud-hypervisor, needs to maintain the list of all
interrupts which needs to be active at all times. This allows to
correctly support multiple devices to be passed through the VM and being
functional at the same time.

Signed-off-by: Sebastien Boeuf <sebastien.boeuf@intel.com>
This commit is contained in:
Sebastien Boeuf 2019-11-27 16:45:10 -08:00 committed by Samuel Ortiz
parent 4115fa8a87
commit 08258d5dad
2 changed files with 129 additions and 104 deletions
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212
vfio/src/vfio_pci.rs
View File

@ -21,9 +21,10 @@ use pci::{
PciSubclass, MSIX_TABLE_ENTRY_SIZE,
};
use std::any::Any;
use std::collections::HashMap;
use std::os::unix::io::AsRawFd;
use std::ptr::null_mut;
use std::sync::Arc;
use std::sync::{Arc, Mutex};
use std::{fmt, io, result};
use vfio_bindings::bindings::vfio::*;
use vm_allocator::SystemAllocator;
@ -38,6 +39,8 @@ pub enum VfioPciError {
NewVfioPciDevice,
MapRegionGuest(kvm_ioctls::Error),
SetGsiRouting(kvm_ioctls::Error),
MsiNotConfigured,
MsixNotConfigured,
}
pub type Result<T> = std::result::Result<T, VfioPciError>;
@ -52,6 +55,8 @@ impl fmt::Display for VfioPciError {
write!(f, "failed to map VFIO PCI region into guest: {}", e)
}
VfioPciError::SetGsiRouting(e) => write!(f, "failed to set GSI routes for KVM: {}", e),
VfioPciError::MsiNotConfigured => write!(f, "MSI interrupt not yet configured"),
VfioPciError::MsixNotConfigured => write!(f, "MSI-X interrupt not yet configured"),
}
}
}
@ -182,22 +187,6 @@ impl Interrupt {
None
}
fn msix_enabled(&self) -> bool {
if let Some(msix) = &self.msix {
return msix.cap.enabled();
}
false
}
fn msix_function_masked(&self) -> bool {
if let Some(msix) = &self.msix {
return msix.cap.masked();
}
false
}
fn msix_table_accessed(&self, bar_index: u32, offset: u64) -> bool {
if let Some(msix) = &self.msix {
return msix.table_accessed(bar_index, offset);
@ -221,30 +210,17 @@ impl Interrupt {
}
}
#[derive(Copy, Clone, Default)]
struct MsiVector {
msg_addr_lo: u32,
msg_addr_hi: u32,
msg_data: u32,
masked: bool,
}
struct InterruptRoute {
gsi: u32,
irq_fd: EventFd,
msi_vector: MsiVector,
}
impl InterruptRoute {
fn new(allocator: &mut SystemAllocator, msi_vector: MsiVector) -> Result<Self> {
fn new(allocator: &mut SystemAllocator) -> Result<Self> {
let irq_fd = EventFd::new(libc::EFD_NONBLOCK).map_err(VfioPciError::EventFd)?;
let gsi = allocator.allocate_gsi().ok_or(VfioPciError::AllocateGsi)?;
Ok(InterruptRoute {
gsi,
irq_fd,
msi_vector,
})
Ok(InterruptRoute { gsi, irq_fd })
}
fn enable(&self, vm: &Arc<VmFd>) -> Result<()> {
@ -322,6 +298,7 @@ pub struct VfioPciDevice {
mmio_regions: Vec<MmioRegion>,
interrupt: Interrupt,
interrupt_routes: Vec<InterruptRoute>,
gsi_msi_routes: Arc<Mutex<HashMap<u32, kvm_irq_routing_entry>>>,
}
impl VfioPciDevice {
@ -330,6 +307,7 @@ impl VfioPciDevice {
vm_fd: &Arc<VmFd>,
allocator: &mut SystemAllocator,
device: VfioDevice,
gsi_msi_routes: Arc<Mutex<HashMap<u32, kvm_irq_routing_entry>>>,
) -> Result<Self> {
let device = Arc::new(device);
device.reset();
@ -359,6 +337,7 @@ impl VfioPciDevice {
msix: None,
},
interrupt_routes: Vec::new(),
gsi_msi_routes,
};
vfio_pci_device.parse_capabilities();
@ -367,8 +346,7 @@ impl VfioPciDevice {
// The MSI vectors will be filled when the guest driver programs the device.
let max_interrupts = vfio_pci_device.device.max_interrupts();
for _ in 0..max_interrupts {
let msi_vector: MsiVector = Default::default();
let route = InterruptRoute::new(allocator, msi_vector)?;
let route = InterruptRoute::new(allocator)?;
vfio_pci_device.interrupt_routes.push(route);
}
@ -396,23 +374,8 @@ impl VfioPciDevice {
fn set_kvm_routes(&self) -> Result<()> {
let mut entry_vec: Vec<kvm_irq_routing_entry> = Vec::new();
for route in self.interrupt_routes.iter() {
// Do not add masked vectors to the GSI mapping
if route.msi_vector.masked {
continue;
}
let mut entry = kvm_irq_routing_entry {
gsi: route.gsi,
type_: KVM_IRQ_ROUTING_MSI,
..Default::default()
};
entry.u.msi.address_lo = route.msi_vector.msg_addr_lo;
entry.u.msi.address_hi = route.msi_vector.msg_addr_hi;
entry.u.msi.data = route.msi_vector.msg_data;
entry_vec.push(entry);
for (_, entry) in self.gsi_msi_routes.lock().unwrap().iter() {
entry_vec.push(*entry);
}
let mut irq_routing =
@ -498,55 +461,94 @@ impl VfioPciDevice {
}
}
fn update_msi_interrupt_routes(&mut self, msi: &VfioMsi) -> Result<()> {
let num_vectors = msi.cap.num_enabled_vectors();
for (idx, route) in self.interrupt_routes.iter_mut().enumerate() {
// Mask the MSI vector if the amount of vectors supported by the
// guest OS does not match the expected amount. This is related
// to "Multiple Message Capable" and "Multiple Message Enable"
// fields from the "Message Control" register.
if idx >= num_vectors {
route.msi_vector.masked = true;
continue;
}
route.msi_vector.msg_addr_lo = msi.cap.msg_addr_lo;
route.msi_vector.msg_addr_hi = msi.cap.msg_addr_hi;
route.msi_vector.msg_data = u32::from(msi.cap.msg_data) | (idx as u32);
route.msi_vector.masked = msi.cap.vector_masked(idx);
}
// Check if we need to update KVM GSI mapping, based on the status of
// the "MSI Enable" bit.
fn update_msi_interrupt_routes(&self, msi: &VfioMsi) -> Result<()> {
if msi.cap.enabled() {
return self.set_kvm_routes();
let mut gsi_msi_routes = self.gsi_msi_routes.lock().unwrap();
for (idx, route) in self.interrupt_routes.iter().enumerate() {
// Ignore MSI vector if the amount of vectors supported by the
// guest OS does not match the expected amount. This is related
// to "Multiple Message Capable" and "Multiple Message Enable"
// fields from the "Message Control" register.
if idx >= msi.cap.num_enabled_vectors() {
continue;
}
// Ignore MSI vector if masked.
if msi.cap.vector_masked(idx) {
continue;
}
let mut entry = kvm_irq_routing_entry {
gsi: route.gsi,
type_: KVM_IRQ_ROUTING_MSI,
..Default::default()
};
entry.u.msi.address_lo = msi.cap.msg_addr_lo;
entry.u.msi.address_hi = msi.cap.msg_addr_hi;
entry.u.msi.data = u32::from(msi.cap.msg_data) | (idx as u32);
gsi_msi_routes.insert(route.gsi, entry);
}
} else {
let mut gsi_msi_routes = self.gsi_msi_routes.lock().unwrap();
for route in self.interrupt_routes.iter() {
gsi_msi_routes.remove(&route.gsi);
}
}
Ok(())
self.set_kvm_routes()
}
fn update_msix_interrupt_routes(&self, msix: &VfioMsix) -> Result<()> {
if msix.cap.enabled() && !msix.cap.masked() {
let mut gsi_msi_routes = self.gsi_msi_routes.lock().unwrap();
for (idx, table_entry) in msix.bar.table_entries.iter().enumerate() {
// Ignore MSI-X vector if masked.
if table_entry.masked() {
continue;
}
let gsi = self.interrupt_routes[idx].gsi;
let mut entry = kvm_irq_routing_entry {
gsi,
type_: KVM_IRQ_ROUTING_MSI,
..Default::default()
};
entry.u.msi.address_lo = table_entry.msg_addr_lo;
entry.u.msi.address_hi = table_entry.msg_addr_hi;
entry.u.msi.data = table_entry.msg_data;
gsi_msi_routes.insert(gsi, entry);
}
} else {
let mut gsi_msi_routes = self.gsi_msi_routes.lock().unwrap();
for route in self.interrupt_routes.iter() {
gsi_msi_routes.remove(&route.gsi);
}
}
self.set_kvm_routes()
}
fn read_msix_table(&mut self, offset: u64, data: &mut [u8]) {
self.interrupt.msix_read_table(offset, data);
}
fn update_msix_table(&mut self, offset: u64, data: &[u8]) -> Result<()> {
fn write_msix_table(&mut self, offset: u64, data: &[u8]) {
self.interrupt.msix_write_table(offset, data);
if self.interrupt.msix_enabled() && !self.interrupt.msix_function_masked() {
// Fill tables
if let Some(msix) = &self.interrupt.msix {
for (idx, entry) in msix.bar.table_entries.iter().enumerate() {
self.interrupt_routes[idx].msi_vector.msg_addr_lo = entry.msg_addr_lo;
self.interrupt_routes[idx].msi_vector.msg_addr_hi = entry.msg_addr_hi;
self.interrupt_routes[idx].msi_vector.msg_data = entry.msg_data;
self.interrupt_routes[idx].msi_vector.masked = entry.masked();
}
if let Some(msix) = &self.interrupt.msix {
if let Err(e) = self.update_msix_interrupt_routes(&msix) {
error!("Could not update MSI-X interrupt routes: {}", e);
}
return self.set_kvm_routes();
}
Ok(())
}
fn update_msi_capabilities(&mut self, offset: u64, data: &[u8]) -> Result<()> {
@ -560,28 +562,29 @@ impl VfioPciDevice {
Err(e) => warn!("Could not get IRQ fds: {}", e),
},
Some(InterruptUpdateAction::DisableMsi) => {
if let Err(e) = self.disable_irq_fds() {
if let Err(e) = self.device.disable_msi() {
warn!("Could not disable MSI: {}", e);
}
if let Err(e) = self.device.disable_msi() {
if let Err(e) = self.disable_irq_fds() {
warn!("Could not disable MSI: {}", e);
}
}
_ => {}
}
// Update the interrupt_routes table now that the MSI cache has been
// Update the gsi_msi_routes table now that the MSI cache has been
// updated. The point is to always update the table based on latest
// changes to the cache, and based on the state of masking flags, the
// KVM GSI routes should be configured.
if let Some(msi) = self.interrupt.msi {
if let Some(msi) = &self.interrupt.msi {
return self.update_msi_interrupt_routes(&msi);
}
Ok(())
// If the code reach this point, something went wrong.
Err(VfioPciError::MsiNotConfigured)
}
fn update_msix_capabilities(&mut self, offset: u64, data: &[u8]) {
fn update_msix_capabilities(&mut self, offset: u64, data: &[u8]) -> Result<()> {
match self.interrupt.update_msix(offset, data) {
Some(InterruptUpdateAction::EnableMsix) => match self.enable_irq_fds() {
Ok(fds) => {
@ -592,15 +595,24 @@ impl VfioPciDevice {
Err(e) => warn!("Could not get IRQ fds: {}", e),
},
Some(InterruptUpdateAction::DisableMsix) => {
if let Err(e) = self.disable_irq_fds() {
warn!("Could not disable MSI: {}", e);
}
if let Err(e) = self.device.disable_msix() {
warn!("Could not disable MSI-X: {}", e);
}
if let Err(e) = self.disable_irq_fds() {
warn!("Could not disable MSI: {}", e);
}
}
_ => {}
}
// Update the gsi_msi_routes table because the state of the enable bit
// changed.
if let Some(msix) = &self.interrupt.msix {
return self.update_msix_interrupt_routes(&msix);
}
// If the code reach this point, something went wrong.
Err(VfioPciError::MsixNotConfigured)
}
fn find_region(&self, addr: u64) -> Option<MmioRegion> {
@ -972,7 +984,9 @@ impl PciDevice for VfioPciDevice {
}
}
PciCapabilityID::MSIX => {
self.update_msix_capabilities(cap_offset, data);
if let Err(e) = self.update_msix_capabilities(cap_offset, data) {
error!("Could not update MSI-X capabilities: {}", e);
}
}
_ => {}
}
@ -1041,9 +1055,7 @@ impl PciDevice for VfioPciDevice {
// If the MSI-X table is written to, we need to update our cache.
if self.interrupt.msix_table_accessed(region.index, offset) {
if let Err(e) = self.update_msix_table(offset, data) {
error!("Could not update MSI-X table: {}", e);
}
self.write_msix_table(offset, data);
} else {
self.device.region_write(region.index, data, offset);
}

21
vmm/src/device_manager.rs
View File

@ -13,7 +13,7 @@ use crate::config::ConsoleOutputMode;
use crate::vm::VmInfo;
use devices::{ioapic, HotPlugNotificationType};
use kvm_bindings::kvm_userspace_memory_region;
use kvm_bindings::{kvm_irq_routing_entry, kvm_userspace_memory_region};
use kvm_ioctls::*;
use libc::O_TMPFILE;
use libc::{EFD_NONBLOCK, TIOCGWINSZ};
@ -30,6 +30,7 @@ use std::fs::{File, OpenOptions};
use std::io::{self, sink, stdout};
use arch::layout::{APIC_START, IOAPIC_SIZE, IOAPIC_START};
use std::collections::HashMap;
use std::os::unix::fs::OpenOptionsExt;
use std::os::unix::io::AsRawFd;
use std::ptr::null_mut;
@ -1273,6 +1274,14 @@ impl DeviceManager {
let mut mem_slot = mem_slots;
let mut iommu_attached_device_ids = Vec::new();
let mut allocator = address_manager.allocator.lock().unwrap();
// Create a shared list of GSI that can be shared through all VFIO
// devices. This way, we can maintain the full list of used GSI,
// preventing one device from overriding interrupts setting from
// another one.
let gsi_msi_routes: Arc<Mutex<HashMap<u32, kvm_irq_routing_entry>>> =
Arc::new(Mutex::new(HashMap::new()));
if let Some(device_list_cfg) = &vm_info.vm_cfg.devices {
// Create the KVM VFIO device
let device_fd = DeviceManager::create_kvm_device(vm_info.vm_fd)?;
@ -1306,9 +1315,13 @@ impl DeviceManager {
}
}
let mut vfio_pci_device =
VfioPciDevice::new(vm_info.vm_fd, &mut allocator, vfio_device)
.map_err(DeviceManagerError::VfioPciCreate)?;
let mut vfio_pci_device = VfioPciDevice::new(
vm_info.vm_fd,
&mut allocator,
vfio_device,
gsi_msi_routes.clone(),
)
.map_err(DeviceManagerError::VfioPciCreate)?;
let bars = vfio_pci_device
.allocate_bars(&mut allocator)