Date: Fri, 30 Sep 2016 01:42:29 +0000 (UTC) From: John Baldwin <jhb@FreeBSD.org> To: src-committers@freebsd.org, svn-src-all@freebsd.org, svn-src-stable@freebsd.org, svn-src-stable-10@freebsd.org Subject: svn commit: r306472 - in stable/10/sys/amd64/vmm: . io Message-ID: <201609300142.u8U1gTWK092222@repo.freebsd.org>
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Author: jhb Date: Fri Sep 30 01:42:29 2016 New Revision: 306472 URL: https://svnweb.freebsd.org/changeset/base/306472 Log: MFC 304858,305485: Fix various issues with PCI pass through and VT-d. 304858: Enable I/O MMU when PCI pass through is first used. Rather than enabling the I/O MMU when the vmm module is loaded, defer initialization until the first attempt to pass a PCI device through to a guest. If the I/O MMU fails to initialize or is not present, than fail the attempt to pass a PCI device through to a guest. The hw.vmm.force_iommu tunable has been removed since the I/O MMU is no longer enabled during boot. However, the I/O MMU support can be disabled by setting the hw.vmm.iommu.enable tunable to 0 to prevent use of the I/O MMU on any systems where it is buggy. 305485: Leave ppt devices in the host domain when they are not attached to a VM. This allows a pass through device to be reset to a normal device driver on the host and reused on the host. ppt devices are now always active in some I/O MMU domain when the I/O MMU is active, either the host domain or the domain of a VM they are attached to. Modified: stable/10/sys/amd64/vmm/io/iommu.c stable/10/sys/amd64/vmm/io/iommu.h stable/10/sys/amd64/vmm/io/ppt.c stable/10/sys/amd64/vmm/vmm.c Directory Properties: stable/10/ (props changed) Modified: stable/10/sys/amd64/vmm/io/iommu.c ============================================================================== --- stable/10/sys/amd64/vmm/io/iommu.c Fri Sep 30 01:39:18 2016 (r306471) +++ stable/10/sys/amd64/vmm/io/iommu.c Fri Sep 30 01:42:29 2016 (r306472) @@ -38,6 +38,7 @@ __FBSDID("$FreeBSD$"); #include <dev/pci/pcivar.h> #include <dev/pci/pcireg.h> +#include <machine/cpu.h> #include <machine/md_var.h> #include "vmm_util.h" @@ -51,6 +52,10 @@ static int iommu_avail; SYSCTL_INT(_hw_vmm_iommu, OID_AUTO, initialized, CTLFLAG_RD, &iommu_avail, 0, "bhyve iommu initialized?"); +static int iommu_enable = 1; +SYSCTL_INT(_hw_vmm_iommu, OID_AUTO, enable, CTLFLAG_RDTUN, &iommu_enable, 0, + "Enable use of I/O MMU (required for PCI passthrough)."); + static struct iommu_ops *ops; static void *host_domain; @@ -148,14 +153,16 @@ IOMMU_DISABLE(void) (*ops->disable)(); } -void +static void iommu_init(void) { int error, bus, slot, func; vm_paddr_t maxaddr; - const char *name; device_t dev; + if (!iommu_enable) + return; + if (vmm_is_intel()) ops = &iommu_ops_intel; else if (vmm_is_amd()) @@ -174,8 +181,13 @@ iommu_init(void) */ maxaddr = vmm_mem_maxaddr(); host_domain = IOMMU_CREATE_DOMAIN(maxaddr); - if (host_domain == NULL) - panic("iommu_init: unable to create a host domain"); + if (host_domain == NULL) { + printf("iommu_init: unable to create a host domain"); + IOMMU_CLEANUP(); + ops = NULL; + iommu_avail = 0; + return; + } /* * Create 1:1 mappings from '0' to 'maxaddr' for devices assigned to @@ -190,12 +202,7 @@ iommu_init(void) if (dev == NULL) continue; - /* skip passthrough devices */ - name = device_get_name(dev); - if (name != NULL && strcmp(name, "ppt") == 0) - continue; - - /* everything else belongs to the host domain */ + /* Everything belongs to the host domain. */ iommu_add_device(host_domain, pci_get_rid(dev)); } @@ -216,7 +223,16 @@ iommu_cleanup(void) void * iommu_create_domain(vm_paddr_t maxaddr) { + static volatile int iommu_initted; + if (iommu_initted < 2) { + if (atomic_cmpset_int(&iommu_initted, 0, 1)) { + iommu_init(); + atomic_store_rel_int(&iommu_initted, 2); + } else + while (iommu_initted == 1) + cpu_spinwait(); + } return (IOMMU_CREATE_DOMAIN(maxaddr)); } Modified: stable/10/sys/amd64/vmm/io/iommu.h ============================================================================== --- stable/10/sys/amd64/vmm/io/iommu.h Fri Sep 30 01:39:18 2016 (r306471) +++ stable/10/sys/amd64/vmm/io/iommu.h Fri Sep 30 01:42:29 2016 (r306472) @@ -61,7 +61,6 @@ struct iommu_ops { extern struct iommu_ops iommu_ops_intel; extern struct iommu_ops iommu_ops_amd; -void iommu_init(void); void iommu_cleanup(void); void *iommu_host_domain(void); void *iommu_create_domain(vm_paddr_t maxaddr); Modified: stable/10/sys/amd64/vmm/io/ppt.c ============================================================================== --- stable/10/sys/amd64/vmm/io/ppt.c Fri Sep 30 01:39:18 2016 (r306471) +++ stable/10/sys/amd64/vmm/io/ppt.c Fri Sep 30 01:42:29 2016 (r306472) @@ -363,6 +363,7 @@ ppt_assign_device(struct vm *vm, int bus return (EBUSY); ppt->vm = vm; + iommu_remove_device(iommu_host_domain(), pci_get_rid(ppt->dev)); iommu_add_device(vm_iommu_domain(vm), pci_get_rid(ppt->dev)); return (0); } @@ -385,6 +386,7 @@ ppt_unassign_device(struct vm *vm, int b ppt_teardown_msi(ppt); ppt_teardown_msix(ppt); iommu_remove_device(vm_iommu_domain(vm), pci_get_rid(ppt->dev)); + iommu_add_device(iommu_host_domain(), pci_get_rid(ppt->dev)); ppt->vm = NULL; return (0); } Modified: stable/10/sys/amd64/vmm/vmm.c ============================================================================== --- stable/10/sys/amd64/vmm/vmm.c Fri Sep 30 01:39:18 2016 (r306471) +++ stable/10/sys/amd64/vmm/vmm.c Fri Sep 30 01:42:29 2016 (r306472) @@ -228,11 +228,6 @@ SYSCTL_INT(_hw_vmm, OID_AUTO, trace_gues &trace_guest_exceptions, 0, "Trap into hypervisor on all guest exceptions and reflect them back"); -static int vmm_force_iommu = 0; -TUNABLE_INT("hw.vmm.force_iommu", &vmm_force_iommu); -SYSCTL_INT(_hw_vmm, OID_AUTO, force_iommu, CTLFLAG_RDTUN, &vmm_force_iommu, 0, - "Force use of I/O MMU even if no passthrough devices were found."); - static void vm_free_memmap(struct vm *vm, int ident); static bool sysmem_mapping(struct vm *vm, struct mem_map *mm); static void vcpu_notify_event_locked(struct vcpu *vcpu, bool lapic_intr); @@ -362,8 +357,6 @@ vmm_handler(module_t mod, int what, void switch (what) { case MOD_LOAD: vmmdev_init(); - if (vmm_force_iommu || ppt_avail_devices() > 0) - iommu_init(); error = vmm_init(); if (error == 0) vmm_initialized = 1; @@ -400,9 +393,6 @@ static moduledata_t vmm_kmod = { /* * vmm initialization has the following dependencies: * - * - iommu initialization must happen after the pci passthru driver has had - * a chance to attach to any passthru devices (after SI_SUB_CONFIGURE). - * * - VT-x initialization requires smp_rendezvous() and therefore must happen * after SMP is fully functional (after SI_SUB_SMP). */ @@ -897,6 +887,8 @@ vm_assign_pptdev(struct vm *vm, int bus, ("vm_assign_pptdev: iommu must be NULL")); maxaddr = sysmem_maxaddr(vm); vm->iommu = iommu_create_domain(maxaddr); + if (vm->iommu == NULL) + return (ENXIO); vm_iommu_map(vm); }
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