From: Andre Przywara <andre.przywara@arm.com>
To: Alexandru Elisei <alexandru.elisei@arm.com>
Cc: kvm@vger.kernel.org, will@kernel.org,
julien.thierry.kdev@gmail.com, sami.mujawar@arm.com,
lorenzo.pieralisi@arm.com
Subject: Re: [PATCH kvmtool 06/16] ioport: pci: Move port allocations to PCI devices
Date: Tue, 28 Jan 2020 18:25:14 +0000 [thread overview]
Message-ID: <20200128182514.52a6095b@donnerap.cambridge.arm.com> (raw)
In-Reply-To: <20191125103033.22694-7-alexandru.elisei@arm.com>
On Mon, 25 Nov 2019 10:30:23 +0000
Alexandru Elisei <alexandru.elisei@arm.com> wrote:
Hi,
> From: Julien Thierry <julien.thierry@arm.com>
>
> The dynamic ioport allocation with IOPORT_EMPTY is currently only used
> by PCI devices. Other devices use fixed ports for which they request
> registration to the ioport API.
>
> PCI ports need to be in the PCI IO space and there is no reason ioport
> API should know a PCI port is being allocated and needs to be placed in
> PCI IO space. This currently just happens to be the case.
>
> Move the responsability of dynamic allocation of ioports from the ioport
> API to PCI.
>
> In the future, if other types of devices also need dynamic ioport
> allocation, they'll have to figure out the range of ports they are
> allowed to use.
That looks alright to me, just one question:
The old ioport__find_free_port() routine used a mutex to prevent concurrent execution.
Why don't we need this anymore? Are we sure that there is only one thread of execution calling this function?
Cheers,
Andre.
> Cc: julien.thierry.kdev@gmail.com
> Signed-off-by: Julien Thierry <julien.thierry@arm.com>
> [Renamed functions for clarity]
> Signed-off-by: Alexandru Elisei <alexandru.elisei@arm.com>
> ---
> hw/vesa.c | 4 ++--
> include/kvm/ioport.h | 3 ---
> include/kvm/pci.h | 4 +++-
> ioport.c | 18 ------------------
> pci.c | 17 +++++++++++++----
> powerpc/include/kvm/kvm-arch.h | 2 +-
> vfio/core.c | 6 ++++--
> vfio/pci.c | 4 ++--
> virtio/pci.c | 7 ++++---
> x86/include/kvm/kvm-arch.h | 2 +-
> 10 files changed, 30 insertions(+), 37 deletions(-)
>
> diff --git a/hw/vesa.c b/hw/vesa.c
> index 75670a51be5f..70ab59974f76 100644
> --- a/hw/vesa.c
> +++ b/hw/vesa.c
> @@ -62,8 +62,8 @@ struct framebuffer *vesa__init(struct kvm *kvm)
>
> if (!kvm->cfg.vnc && !kvm->cfg.sdl && !kvm->cfg.gtk)
> return NULL;
> -
> - r = ioport__register(kvm, IOPORT_EMPTY, &vesa_io_ops, IOPORT_SIZE, NULL);
> + r = pci_get_io_port_block(IOPORT_SIZE);
> + r = ioport__register(kvm, r, &vesa_io_ops, IOPORT_SIZE, NULL);
> if (r < 0)
> return ERR_PTR(r);
>
> diff --git a/include/kvm/ioport.h b/include/kvm/ioport.h
> index db52a479742b..b10fcd5b4412 100644
> --- a/include/kvm/ioport.h
> +++ b/include/kvm/ioport.h
> @@ -14,11 +14,8 @@
>
> /* some ports we reserve for own use */
> #define IOPORT_DBG 0xe0
> -#define IOPORT_START 0x6200
> #define IOPORT_SIZE 0x400
>
> -#define IOPORT_EMPTY USHRT_MAX
> -
> struct kvm;
>
> struct ioport {
> diff --git a/include/kvm/pci.h b/include/kvm/pci.h
> index a86c15a70e6d..ccb155e3e8fe 100644
> --- a/include/kvm/pci.h
> +++ b/include/kvm/pci.h
> @@ -19,6 +19,7 @@
> #define PCI_CONFIG_DATA 0xcfc
> #define PCI_CONFIG_BUS_FORWARD 0xcfa
> #define PCI_IO_SIZE 0x100
> +#define PCI_IOPORT_START 0x6200
> #define PCI_CFG_SIZE (1ULL << 24)
>
> struct kvm;
> @@ -152,7 +153,8 @@ struct pci_device_header {
> int pci__init(struct kvm *kvm);
> int pci__exit(struct kvm *kvm);
> struct pci_device_header *pci__find_dev(u8 dev_num);
> -u32 pci_get_io_space_block(u32 size);
> +u32 pci_get_mmio_block(u32 size);
> +u16 pci_get_io_port_block(u32 size);
> void pci__assign_irq(struct device_header *dev_hdr);
> void pci__config_wr(struct kvm *kvm, union pci_config_address addr, void *data, int size);
> void pci__config_rd(struct kvm *kvm, union pci_config_address addr, void *data, int size);
> diff --git a/ioport.c b/ioport.c
> index a6dc65e3e6c6..a72e4035881a 100644
> --- a/ioport.c
> +++ b/ioport.c
> @@ -16,24 +16,8 @@
>
> #define ioport_node(n) rb_entry(n, struct ioport, node)
>
> -DEFINE_MUTEX(ioport_mutex);
> -
> -static u16 free_io_port_idx; /* protected by ioport_mutex */
> -
> static struct rb_root ioport_tree = RB_ROOT;
>
> -static u16 ioport__find_free_port(void)
> -{
> - u16 free_port;
> -
> - mutex_lock(&ioport_mutex);
> - free_port = IOPORT_START + free_io_port_idx * IOPORT_SIZE;
> - free_io_port_idx++;
> - mutex_unlock(&ioport_mutex);
> -
> - return free_port;
> -}
> -
> static struct ioport *ioport_search(struct rb_root *root, u64 addr)
> {
> struct rb_int_node *node;
> @@ -85,8 +69,6 @@ int ioport__register(struct kvm *kvm, u16 port, struct ioport_operations *ops, i
> int r;
>
> br_write_lock(kvm);
> - if (port == IOPORT_EMPTY)
> - port = ioport__find_free_port();
>
> entry = ioport_search(&ioport_tree, port);
> if (entry) {
> diff --git a/pci.c b/pci.c
> index e1b57325bdeb..32a07335a765 100644
> --- a/pci.c
> +++ b/pci.c
> @@ -15,15 +15,24 @@ static u32 pci_config_address_bits;
> * (That's why it can still 32bit even with 64bit guests-- 64bit
> * PCI isn't currently supported.)
> */
> -static u32 io_space_blocks = KVM_PCI_MMIO_AREA;
> +static u32 mmio_blocks = KVM_PCI_MMIO_AREA;
> +static u16 io_port_blocks = PCI_IOPORT_START;
> +
> +u16 pci_get_io_port_block(u32 size)
> +{
> + u16 port = ALIGN(io_port_blocks, IOPORT_SIZE);
> +
> + io_port_blocks = port + size;
> + return port;
> +}
>
> /*
> * BARs must be naturally aligned, so enforce this in the allocator.
> */
> -u32 pci_get_io_space_block(u32 size)
> +u32 pci_get_mmio_block(u32 size)
> {
> - u32 block = ALIGN(io_space_blocks, size);
> - io_space_blocks = block + size;
> + u32 block = ALIGN(mmio_blocks, size);
> + mmio_blocks = block + size;
> return block;
> }
>
> diff --git a/powerpc/include/kvm/kvm-arch.h b/powerpc/include/kvm/kvm-arch.h
> index 8126b96cb66a..26d440b22bdd 100644
> --- a/powerpc/include/kvm/kvm-arch.h
> +++ b/powerpc/include/kvm/kvm-arch.h
> @@ -34,7 +34,7 @@
> #define KVM_MMIO_START PPC_MMIO_START
>
> /*
> - * This is the address that pci_get_io_space_block() starts allocating
> + * This is the address that pci_get_io_port_block() starts allocating
> * from. Note that this is a PCI bus address.
> */
> #define KVM_IOPORT_AREA 0x0
> diff --git a/vfio/core.c b/vfio/core.c
> index 17b5b0cfc9ac..0ed1e6fee6bf 100644
> --- a/vfio/core.c
> +++ b/vfio/core.c
> @@ -202,8 +202,10 @@ static int vfio_setup_trap_region(struct kvm *kvm, struct vfio_device *vdev,
> struct vfio_region *region)
> {
> if (region->is_ioport) {
> - int port = ioport__register(kvm, IOPORT_EMPTY, &vfio_ioport_ops,
> - region->info.size, region);
> + int port = pci_get_io_port_block(region->info.size);
> +
> + port = ioport__register(kvm, port, &vfio_ioport_ops,
> + region->info.size, region);
> if (port < 0)
> return port;
>
> diff --git a/vfio/pci.c b/vfio/pci.c
> index 914732cc6897..bc5a6d452f7a 100644
> --- a/vfio/pci.c
> +++ b/vfio/pci.c
> @@ -750,7 +750,7 @@ static int vfio_pci_create_msix_table(struct kvm *kvm,
> * powers of two.
> */
> mmio_size = roundup_pow_of_two(table->size + pba->size);
> - table->guest_phys_addr = pci_get_io_space_block(mmio_size);
> + table->guest_phys_addr = pci_get_mmio_block(mmio_size);
> if (!table->guest_phys_addr) {
> pr_err("cannot allocate IO space");
> ret = -ENOMEM;
> @@ -851,7 +851,7 @@ static int vfio_pci_configure_bar(struct kvm *kvm, struct vfio_device *vdev,
> if (!region->is_ioport) {
> /* Grab some MMIO space in the guest */
> map_size = ALIGN(region->info.size, PAGE_SIZE);
> - region->guest_phys_addr = pci_get_io_space_block(map_size);
> + region->guest_phys_addr = pci_get_mmio_block(map_size);
> }
>
> /* Map the BARs into the guest or setup a trap region. */
> diff --git a/virtio/pci.c b/virtio/pci.c
> index 04e801827df9..d73414abde05 100644
> --- a/virtio/pci.c
> +++ b/virtio/pci.c
> @@ -438,18 +438,19 @@ int virtio_pci__init(struct kvm *kvm, void *dev, struct virtio_device *vdev,
> BUILD_BUG_ON(!is_power_of_two(IOPORT_SIZE));
> BUILD_BUG_ON(!is_power_of_two(PCI_IO_SIZE));
>
> - r = ioport__register(kvm, IOPORT_EMPTY, &virtio_pci__io_ops, IOPORT_SIZE, vdev);
> + r = pci_get_io_port_block(IOPORT_SIZE);
> + r = ioport__register(kvm, r, &virtio_pci__io_ops, IOPORT_SIZE, vdev);
> if (r < 0)
> return r;
> vpci->port_addr = (u16)r;
>
> - vpci->mmio_addr = pci_get_io_space_block(IOPORT_SIZE);
> + vpci->mmio_addr = pci_get_mmio_block(IOPORT_SIZE);
> r = kvm__register_mmio(kvm, vpci->mmio_addr, IOPORT_SIZE, false,
> virtio_pci__io_mmio_callback, vpci);
> if (r < 0)
> goto free_ioport;
>
> - vpci->msix_io_block = pci_get_io_space_block(PCI_IO_SIZE * 2);
> + vpci->msix_io_block = pci_get_mmio_block(PCI_IO_SIZE * 2);
> r = kvm__register_mmio(kvm, vpci->msix_io_block, PCI_IO_SIZE * 2, false,
> virtio_pci__msix_mmio_callback, vpci);
> if (r < 0)
> diff --git a/x86/include/kvm/kvm-arch.h b/x86/include/kvm/kvm-arch.h
> index bfdd3438a9de..85cd336c7577 100644
> --- a/x86/include/kvm/kvm-arch.h
> +++ b/x86/include/kvm/kvm-arch.h
> @@ -16,7 +16,7 @@
>
> #define KVM_MMIO_START KVM_32BIT_GAP_START
>
> -/* This is the address that pci_get_io_space_block() starts allocating
> +/* This is the address that pci_get_io_port_block() starts allocating
> * from. Note that this is a PCI bus address (though same on x86).
> */
> #define KVM_IOPORT_AREA 0x0
next prev parent reply other threads:[~2020-01-28 18:25 UTC|newest]
Thread overview: 37+ messages / expand[flat|nested] mbox.gz Atom feed top
2019-11-25 10:30 [PATCH kvmtool 00/16] Add writable BARs and PCIE 1.1 support Alexandru Elisei
2019-11-25 10:30 ` [PATCH kvmtool 01/16] Makefile: Use correct objcopy binary when cross-compiling for x86_64 Alexandru Elisei
2019-11-27 18:23 ` Andre Przywara
2019-11-25 10:30 ` [PATCH kvmtool 02/16] pci: Fix BAR resource sizing arbitration Alexandru Elisei
2019-11-27 18:24 ` Andre Przywara
2019-11-28 9:37 ` Alexandru Elisei
2019-11-25 10:30 ` [PATCH kvmtool 03/16] Remove pci-shmem device Alexandru Elisei
2019-11-27 18:24 ` Andre Przywara
2019-11-25 10:30 ` [PATCH kvmtool 04/16] Check that a PCI device's memory size is power of two Alexandru Elisei
2019-11-27 18:25 ` Andre Przywara
2020-01-15 12:43 ` Alexandru Elisei
2020-01-15 14:07 ` Andre Przywara
2020-01-15 15:00 ` Alexandru Elisei
2019-11-25 10:30 ` [PATCH kvmtool 05/16] arm: pci.c: Advertise only PCI bus 0 in the DT Alexandru Elisei
2019-11-28 17:43 ` Andre Przywara
2020-01-15 14:49 ` Alexandru Elisei
2019-11-25 10:30 ` [PATCH kvmtool 06/16] ioport: pci: Move port allocations to PCI devices Alexandru Elisei
2020-01-28 18:25 ` Andre Przywara [this message]
2020-01-29 10:07 ` Alexandru Elisei
2020-01-29 10:29 ` Andre Przywara
2019-11-25 10:30 ` [PATCH kvmtool 07/16] pci: Fix ioport allocation size Alexandru Elisei
2020-01-28 18:26 ` Andre Przywara
2020-01-29 11:11 ` Alexandru Elisei
2019-11-25 10:30 ` [PATCH kvmtool 08/16] arm/pci: Fix PCI IO region Alexandru Elisei
2019-11-25 10:30 ` [PATCH kvmtool 09/16] arm/pci: Do not use first PCI IO space bytes for devices Alexandru Elisei
2019-12-02 12:15 ` Lorenzo Pieralisi
2020-01-15 15:08 ` Alexandru Elisei
2019-11-25 10:30 ` [PATCH kvmtool 10/16] virtio/pci: Make memory and IO BARs independent Alexandru Elisei
2019-11-25 10:30 ` [PATCH kvmtool 11/16] virtio/pci: Ignore MMIO and I/O accesses when they are disabled Alexandru Elisei
2019-11-25 10:30 ` [PATCH kvmtool 12/16] Use independent read/write locks for ioport and mmio Alexandru Elisei
2019-11-25 10:30 ` [PATCH kvmtool 13/16] vfio: Add support for BAR configuration Alexandru Elisei
2019-11-29 17:05 ` Alexandru Elisei
2019-11-25 10:30 ` [PATCH kvmtool 14/16] virtio/pci: " Alexandru Elisei
2019-11-25 10:30 ` [PATCH kvmtool 15/16] arm/fdt: Remove 'linux,pci-probe-only' property Alexandru Elisei
2019-11-25 10:30 ` [PATCH kvmtool 16/16] Add PCI Express 1.1 support Alexandru Elisei
2019-11-28 17:41 ` [PATCH kvmtool 00/16] Add writable BARs and PCIE " Lorenzo Pieralisi
2020-01-15 15:10 ` Alexandru Elisei
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