From: Andre Przywara <andre.przywara@arm.com>
To: Alexandru Elisei <alexandru.elisei@arm.com>
Cc: Will Deacon <will@kernel.org>,
Julien Thierry <julien.thierry.kdev@gmail.com>,
kvm@vger.kernel.org, kvmarm@lists.cs.columbia.edu,
linux-arm-kernel@lists.infradead.org,
Marc Zyngier <maz@kernel.org>
Subject: Re: [PATCH kvmtool 09/21] x86/ioport: Switch to new trap handlers
Date: Thu, 18 Feb 2021 14:05:29 +0000 [thread overview]
Message-ID: <20210218140529.1d23c397@slackpad.fritz.box> (raw)
In-Reply-To: <b5eb332b-392e-3b4f-8797-9b7a1e4b5e56@arm.com>
On Fri, 12 Feb 2021 11:27:59 +0000
Alexandru Elisei <alexandru.elisei@arm.com> wrote:
Hi Alex,
> On 12/10/20 2:28 PM, Andre Przywara wrote:
> > Now that the x86 I/O ports have trap handlers adhering to the MMIO fault
> > handler prototype, let's switch over to the joint registration routine.
> >
> > This allows us to get rid of the ioport shim routines.
> >
> > Signed-off-by: Andre Przywara <andre.przywara@arm.com>
> > ---
> > x86/ioport.c | 113 ++++++++++++++-------------------------------------
> > 1 file changed, 30 insertions(+), 83 deletions(-)
> >
> > diff --git a/x86/ioport.c b/x86/ioport.c
> > index 932da20a..87955da1 100644
> > --- a/x86/ioport.c
> > +++ b/x86/ioport.c
> > @@ -8,16 +8,6 @@ static void dummy_mmio(struct kvm_cpu *vcpu, u64 addr, u8 *data, u32 len,
> > {
> > }
> >
> > -static bool debug_io_out(struct ioport *ioport, struct kvm_cpu *vcpu, u16 port, void *data, int size)
> > -{
> > - dummy_mmio(vcpu, port, data, size, true, NULL);
> > - return 0;
> > -}
>
> 0 is false in boolean logic, which means that emulation fails according to the
> (old) ioport emulation code (ioport.c::kvm__emulate_io()).
>
> So I guess I have a few questions:
>
> - Is this a bug in the emulation code, where the author thought that
> debug_io_out() returns an int, and in that case 0 actually means success?
Wading through the swamp of the git history it looks like failure is
intentional, it should be used together with --debug-ioport, to trigger
that print there.
> - If writing to the debug port is rightfully considered an error, do we care
> enough about it to print something to stdout like kvm__emulate_io() does when
> debug_io_out() returns false?
I think you are right, we should print something here.
Cheers,
Andre
> > -
> > -static struct ioport_operations debug_ops = {
> > - .io_out = debug_io_out,
> > -};
> > -
> > static void seabios_debug_mmio(struct kvm_cpu *vcpu, u64 addr, u8 *data,
> > u32 len, u8 is_write, void *ptr)
> > {
> > @@ -31,37 +21,6 @@ static void seabios_debug_mmio(struct kvm_cpu *vcpu, u64 addr, u8 *data,
> > putchar(ch);
> > }
> >
> > -static bool seabios_debug_io_out(struct ioport *ioport, struct kvm_cpu *vcpu, u16 port, void *data, int size)
> > -{
> > - seabios_debug_mmio(vcpu, port, data, size, true, NULL);
> > - return 0;
> > -}
> > -
> > -static struct ioport_operations seabios_debug_ops = {
> > - .io_out = seabios_debug_io_out,
> > -};
> > -
> > -static bool dummy_io_in(struct ioport *ioport, struct kvm_cpu *vcpu, u16 port, void *data, int size)
> > -{
> > - dummy_mmio(vcpu, port, data, size, false, NULL);
> > - return true;
> > -}
> > -
> > -static bool dummy_io_out(struct ioport *ioport, struct kvm_cpu *vcpu, u16 port, void *data, int size)
> > -{
> > - dummy_mmio(vcpu, port, data, size, true, NULL);
> > - return true;
> > -}
> > -
> > -static struct ioport_operations dummy_read_write_ioport_ops = {
> > - .io_in = dummy_io_in,
> > - .io_out = dummy_io_out,
> > -};
> > -
> > -static struct ioport_operations dummy_write_only_ioport_ops = {
> > - .io_out = dummy_io_out,
> > -};
> > -
> > /*
> > * The "fast A20 gate"
> > */
> > @@ -76,17 +35,6 @@ static void ps2_control_mmio(struct kvm_cpu *vcpu, u64 addr, u8 *data, u32 len,
> > ioport__write8(data, 0x02);
> > }
> >
> > -static bool ps2_control_a_io_in(struct ioport *ioport, struct kvm_cpu *vcpu, u16 port, void *data, int size)
> > -{
> > - ps2_control_mmio(vcpu, port, data, size, false, NULL);
> > - return true;
> > -}
> > -
> > -static struct ioport_operations ps2_control_a_ops = {
> > - .io_in = ps2_control_a_io_in,
> > - .io_out = dummy_io_out,
> > -};
> > -
> > void ioport__map_irq(u8 *irq)
> > {
> > }
> > @@ -98,75 +46,75 @@ static int ioport__setup_arch(struct kvm *kvm)
> > /* Legacy ioport setup */
> >
> > /* 0000 - 001F - DMA1 controller */
> > - r = ioport__register(kvm, 0x0000, &dummy_read_write_ioport_ops, 32, NULL);
> > + r = kvm__register_pio(kvm, 0x0000, 32, dummy_mmio, NULL);
> > if (r < 0)
> > return r;
> >
> > /* 0x0020 - 0x003F - 8259A PIC 1 */
> > - r = ioport__register(kvm, 0x0020, &dummy_read_write_ioport_ops, 2, NULL);
> > + r = kvm__register_pio(kvm, 0x0020, 2, dummy_mmio, NULL);
> > if (r < 0)
> > return r;
> >
> > /* PORT 0040-005F - PIT - PROGRAMMABLE INTERVAL TIMER (8253, 8254) */
> > - r = ioport__register(kvm, 0x0040, &dummy_read_write_ioport_ops, 4, NULL);
> > + r = kvm__register_pio(kvm, 0x0040, 4, dummy_mmio, NULL);
> > if (r < 0)
> > return r;
> >
> > /* 0092 - PS/2 system control port A */
> > - r = ioport__register(kvm, 0x0092, &ps2_control_a_ops, 1, NULL);
> > + r = kvm__register_pio(kvm, 0x0092, 1, ps2_control_mmio, NULL);
> > if (r < 0)
> > return r;
> >
> > /* 0x00A0 - 0x00AF - 8259A PIC 2 */
> > - r = ioport__register(kvm, 0x00A0, &dummy_read_write_ioport_ops, 2, NULL);
> > + r = kvm__register_pio(kvm, 0x00A0, 2, dummy_mmio, NULL);
> > if (r < 0)
> > return r;
> >
> > /* 00C0 - 001F - DMA2 controller */
> > - r = ioport__register(kvm, 0x00C0, &dummy_read_write_ioport_ops, 32, NULL);
> > + r = kvm__register_pio(kvm, 0x00c0, 32, dummy_mmio, NULL);
> > if (r < 0)
> > return r;
> >
> > /* PORT 00E0-00EF are 'motherboard specific' so we use them for our
> > internal debugging purposes. */
> > - r = ioport__register(kvm, IOPORT_DBG, &debug_ops, 1, NULL);
> > + r = kvm__register_pio(kvm, IOPORT_DBG, 1, dummy_mmio, NULL);
> > if (r < 0)
> > return r;
> >
> > /* PORT 00ED - DUMMY PORT FOR DELAY??? */
> > - r = ioport__register(kvm, 0x00ED, &dummy_write_only_ioport_ops, 1, NULL);
> > + r = kvm__register_pio(kvm, 0x00ed, 1, dummy_mmio, NULL);
> > if (r < 0)
> > return r;
> >
> > /* 0x00F0 - 0x00FF - Math co-processor */
> > - r = ioport__register(kvm, 0x00F0, &dummy_write_only_ioport_ops, 2, NULL);
> > + r = kvm__register_pio(kvm, 0x00f0, 2, dummy_mmio, NULL);
> > if (r < 0)
> > return r;
> >
> > /* PORT 0278-027A - PARALLEL PRINTER PORT (usually LPT1, sometimes LPT2) */
> > - r = ioport__register(kvm, 0x0278, &dummy_read_write_ioport_ops, 3, NULL);
> > + r = kvm__register_pio(kvm, 0x0278, 3, dummy_mmio, NULL);
> > if (r < 0)
> > return r;
> >
> > /* PORT 0378-037A - PARALLEL PRINTER PORT (usually LPT2, sometimes LPT3) */
> > - r = ioport__register(kvm, 0x0378, &dummy_read_write_ioport_ops, 3, NULL);
> > + r = kvm__register_pio(kvm, 0x0378, 3, dummy_mmio, NULL);
> > if (r < 0)
> > return r;
> >
> > /* PORT 03D4-03D5 - COLOR VIDEO - CRT CONTROL REGISTERS */
> > - r = ioport__register(kvm, 0x03D4, &dummy_read_write_ioport_ops, 1, NULL);
> > + r = kvm__register_pio(kvm, 0x03d4, 1, dummy_mmio, NULL);
> > if (r < 0)
> > return r;
> > - r = ioport__register(kvm, 0x03D5, &dummy_write_only_ioport_ops, 1, NULL);
> > + r = kvm__register_pio(kvm, 0x03d5, 1, dummy_mmio, NULL);
> > if (r < 0)
> > return r;
> >
> > - r = ioport__register(kvm, 0x402, &seabios_debug_ops, 1, NULL);
> > + r = kvm__register_pio(kvm, 0x0402, 1, seabios_debug_mmio, NULL);
> > if (r < 0)
> > return r;
> >
> > /* 0510 - QEMU BIOS configuration register */
> > - r = ioport__register(kvm, 0x510, &dummy_read_write_ioport_ops, 2, NULL);
> > + r = kvm__register_pio(kvm, 0x0510, 2, dummy_mmio, NULL);
> > if (r < 0)
> > return r;
> >
> > @@ -176,22 +124,21 @@ dev_base_init(ioport__setup_arch);
> >
> > static int ioport__remove_arch(struct kvm *kvm)
> > {
> > - ioport__unregister(kvm, 0x510);
> > - ioport__unregister(kvm, 0x402);
> > - ioport__unregister(kvm, 0x03D5);
> > - ioport__unregister(kvm, 0x03D4);
> > - ioport__unregister(kvm, 0x0378);
> > - ioport__unregister(kvm, 0x0278);
> > - ioport__unregister(kvm, 0x00F0);
> > - ioport__unregister(kvm, 0x00ED);
> > - ioport__unregister(kvm, IOPORT_DBG);
> > - ioport__unregister(kvm, 0x00C0);
> > - ioport__unregister(kvm, 0x00A0);
> > - ioport__unregister(kvm, 0x0092);
> > - ioport__unregister(kvm, 0x0040);
> > - ioport__unregister(kvm, 0x0020);
> > - ioport__unregister(kvm, 0x0000);
> > -
> > + kvm__deregister_pio(kvm, 0x510);
> > + kvm__deregister_pio(kvm, 0x402);
> > + kvm__deregister_pio(kvm, 0x3d5);
> > + kvm__deregister_pio(kvm, 0x3d4);
> > + kvm__deregister_pio(kvm, 0x378);
> > + kvm__deregister_pio(kvm, 0x278);
> > + kvm__deregister_pio(kvm, 0x0f0);
> > + kvm__deregister_pio(kvm, 0x0ed);
> > + kvm__deregister_pio(kvm, IOPORT_DBG);
> > + kvm__deregister_pio(kvm, 0x0c0);
> > + kvm__deregister_pio(kvm, 0x0a0);
> > + kvm__deregister_pio(kvm, 0x092);
> > + kvm__deregister_pio(kvm, 0x040);
> > + kvm__deregister_pio(kvm, 0x020);
> > + kvm__deregister_pio(kvm, 0x000);
> > return 0;
> > }
> > dev_base_exit(ioport__remove_arch);
next prev parent reply other threads:[~2021-02-18 16:15 UTC|newest]
Thread overview: 72+ messages / expand[flat|nested] mbox.gz Atom feed top
2020-12-10 14:28 [PATCH kvmtool 00/21] Unify I/O port and MMIO trap handling Andre Przywara
2020-12-10 14:28 ` [PATCH kvmtool 01/21] ioport: Remove ioport__setup_arch() Andre Przywara
2021-02-10 17:44 ` Alexandru Elisei
2021-02-11 17:16 ` Andre Przywara
2021-02-11 17:32 ` Alexandru Elisei
2021-02-17 16:46 ` Andre Przywara
2021-02-22 10:23 ` Andre Przywara
2021-02-22 15:01 ` Alexandru Elisei
2020-12-10 14:28 ` [PATCH kvmtool 02/21] hw/serial: Use device abstraction for FDT generator function Andre Przywara
2021-02-11 12:05 ` Alexandru Elisei
2021-02-11 17:45 ` Andre Przywara
2020-12-10 14:28 ` [PATCH kvmtool 03/21] ioport: Retire .generate_fdt_node functionality Andre Przywara
2021-02-11 14:05 ` Alexandru Elisei
2021-02-17 15:54 ` Andre Przywara
2021-02-17 16:06 ` Alexandru Elisei
2020-12-10 14:28 ` [PATCH kvmtool 04/21] mmio: Extend handling to include ioport emulation Andre Przywara
2021-02-11 16:10 ` Alexandru Elisei
2021-02-17 17:43 ` Andre Przywara
2021-02-22 15:50 ` Alexandru Elisei
2020-12-10 14:28 ` [PATCH kvmtool 05/21] hw/i8042: Clean up data types Andre Przywara
2021-02-11 16:55 ` Alexandru Elisei
2021-02-17 17:46 ` Andre Przywara
2020-12-10 14:28 ` [PATCH kvmtool 06/21] hw/i8042: Refactor trap handler Andre Przywara
2021-02-11 17:23 ` Alexandru Elisei
2021-02-18 10:34 ` Andre Przywara
2021-02-18 11:17 ` Alexandru Elisei
2021-02-18 11:48 ` Andre Przywara
2021-02-22 16:03 ` Alexandru Elisei
2020-12-10 14:28 ` [PATCH kvmtool 07/21] hw/i8042: Switch to new trap handlers Andre Przywara
2021-02-12 10:41 ` Alexandru Elisei
2021-02-18 12:09 ` Andre Przywara
2021-02-22 16:19 ` Alexandru Elisei
2020-12-10 14:28 ` [PATCH kvmtool 08/21] x86/ioport: Refactor " Andre Przywara
2021-02-12 11:14 ` Alexandru Elisei
2020-12-10 14:28 ` [PATCH kvmtool 09/21] x86/ioport: Switch to new " Andre Przywara
2021-02-12 11:27 ` Alexandru Elisei
2021-02-18 14:05 ` Andre Przywara [this message]
2020-12-10 14:28 ` [PATCH kvmtool 10/21] hw/rtc: Refactor " Andre Przywara
2021-02-12 11:56 ` Alexandru Elisei
2020-12-10 14:28 ` [PATCH kvmtool 11/21] hw/rtc: Switch to new trap handler Andre Przywara
2021-02-12 12:02 ` Alexandru Elisei
2020-12-10 14:28 ` [PATCH kvmtool 12/21] hw/vesa: Switch trap handling to use MMIO handler Andre Przywara
2021-02-12 17:50 ` Alexandru Elisei
2020-12-10 14:29 ` [PATCH kvmtool 13/21] hw/serial: Refactor trap handler Andre Przywara
2021-02-16 14:22 ` Alexandru Elisei
2021-02-18 14:41 ` Andre Przywara
2021-02-22 17:40 ` Alexandru Elisei
2021-02-24 14:54 ` Andre Przywara
2020-12-10 14:29 ` [PATCH kvmtool 14/21] hw/serial: Switch to new trap handlers Andre Przywara
2021-02-16 14:31 ` Alexandru Elisei
2020-12-10 14:29 ` [PATCH kvmtool 15/21] vfio: Refactor ioport trap handler Andre Przywara
2021-02-16 14:47 ` Alexandru Elisei
2021-02-18 15:51 ` Andre Przywara
2020-12-10 14:29 ` [PATCH kvmtool 16/21] vfio: Switch to new ioport trap handlers Andre Przywara
2021-02-16 14:52 ` Alexandru Elisei
2020-12-10 14:29 ` [PATCH kvmtool 17/21] virtio: Switch trap handling to use MMIO handler Andre Przywara
2021-02-16 17:03 ` Alexandru Elisei
2021-02-18 16:13 ` Andre Przywara
2020-12-10 14:29 ` [PATCH kvmtool 18/21] pci: " Andre Przywara
2021-02-17 15:14 ` Alexandru Elisei
2020-12-10 14:29 ` [PATCH kvmtool 19/21] Remove ioport specific routines Andre Przywara
2021-02-17 15:49 ` Alexandru Elisei
2021-02-17 16:11 ` Alexandru Elisei
2021-02-18 16:34 ` Andre Przywara
2020-12-10 14:29 ` [PATCH kvmtool 20/21] hw/serial: ARM/arm64: Use MMIO at higher addresses Andre Przywara
2021-02-17 16:48 ` Alexandru Elisei
2021-02-18 12:18 ` Alexandru Elisei
2021-02-18 16:38 ` Andre Przywara
2020-12-10 14:29 ` [PATCH kvmtool 21/21] hw/rtc: " Andre Przywara
2021-02-18 13:33 ` Alexandru Elisei
2021-02-18 16:41 ` Andre Przywara
2021-02-10 17:44 ` [PATCH kvmtool 00/21] Unify I/O port and MMIO trap handling Alexandru Elisei
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