From: Paolo Bonzini <pbonzini@redhat.com>
To: linux-kernel@vger.kernel.org, kvm@vger.kernel.org
Cc: mlevitsk@redhat.com, seanjc@google.com
Subject: [PATCH 08/13] KVM: x86: inline kernel_pio into its sole caller
Date: Fri, 22 Oct 2021 11:36:11 -0400 [thread overview]
Message-ID: <20211022153616.1722429-9-pbonzini@redhat.com> (raw)
In-Reply-To: <20211022153616.1722429-1-pbonzini@redhat.com>
The caller of kernel_pio already has arguments for most of what kernel_pio
fishes out of vcpu->arch.pio. This is the first step towards ensuring that
vcpu->arch.pio.* is only used when exiting to userspace.
We can now also WARN if emulated PIO performs successful in-kernel iterations
before having to fall back to userspace. The code is not ready for that, and
it should never happen.
No functional change intended.
Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
---
arch/x86/kvm/x86.c | 39 +++++++++++++++++----------------------
1 file changed, 17 insertions(+), 22 deletions(-)
diff --git a/arch/x86/kvm/x86.c b/arch/x86/kvm/x86.c
index b26647a5ea22..d6b8df7cea80 100644
--- a/arch/x86/kvm/x86.c
+++ b/arch/x86/kvm/x86.c
@@ -6886,37 +6886,32 @@ static int emulator_cmpxchg_emulated(struct x86_emulate_ctxt *ctxt,
return emulator_write_emulated(ctxt, addr, new, bytes, exception);
}
-static int kernel_pio(struct kvm_vcpu *vcpu, void *pd)
-{
- int r = 0, i;
-
- for (i = 0; i < vcpu->arch.pio.count; i++) {
- if (vcpu->arch.pio.in)
- r = kvm_io_bus_read(vcpu, KVM_PIO_BUS, vcpu->arch.pio.port,
- vcpu->arch.pio.size, pd);
- else
- r = kvm_io_bus_write(vcpu, KVM_PIO_BUS,
- vcpu->arch.pio.port, vcpu->arch.pio.size,
- pd);
- if (r)
- break;
- pd += vcpu->arch.pio.size;
- }
- return r;
-}
-
static int emulator_pio_in_out(struct kvm_vcpu *vcpu, int size,
unsigned short port,
unsigned int count, bool in)
{
+ void *data = vcpu->arch.pio_data;
+ unsigned i;
+ int r;
+
vcpu->arch.pio.port = port;
vcpu->arch.pio.in = in;
- vcpu->arch.pio.count = count;
+ vcpu->arch.pio.count = count;
vcpu->arch.pio.size = size;
- if (!kernel_pio(vcpu, vcpu->arch.pio_data))
- return 1;
+ for (i = 0; i < count; i++) {
+ if (in)
+ r = kvm_io_bus_read(vcpu, KVM_PIO_BUS, port, size, data);
+ else
+ r = kvm_io_bus_write(vcpu, KVM_PIO_BUS, port, size, data);
+ if (r)
+ goto userspace_io;
+ data += size;
+ }
+ return 1;
+userspace_io:
+ WARN_ON(i != 0);
vcpu->run->exit_reason = KVM_EXIT_IO;
vcpu->run->io.direction = in ? KVM_EXIT_IO_IN : KVM_EXIT_IO_OUT;
vcpu->run->io.size = size;
--
2.27.0
next prev parent reply other threads:[~2021-10-22 15:36 UTC|newest]
Thread overview: 20+ messages / expand[flat|nested] mbox.gz Atom feed top
2021-10-22 15:36 [PATCH v2 00/13] fixes and cleanups for string I/O emulation Paolo Bonzini
2021-10-22 15:36 ` [PATCH 01/13] KVM: SEV-ES: rename guest_ins_data to sev_pio_data Paolo Bonzini
2021-10-22 15:36 ` [PATCH 02/13] KVM: x86: leave vcpu->arch.pio.count alone in emulator_pio_in_out Paolo Bonzini
2021-10-22 15:36 ` [PATCH 03/13] KVM: SEV-ES: clean up kvm_sev_es_ins/outs Paolo Bonzini
2021-10-22 15:36 ` [PATCH 04/13] KVM: x86: split the two parts of emulator_pio_in Paolo Bonzini
2021-10-22 15:36 ` [PATCH 05/13] KVM: x86: remove unnecessary arguments from complete_emulator_pio_in Paolo Bonzini
2021-10-22 15:36 ` [PATCH 06/13] KVM: SEV-ES: keep INS functions together Paolo Bonzini
2021-10-22 15:36 ` [PATCH 07/13] KVM: SEV-ES: go over the sev_pio_data buffer in multiple passes if needed Paolo Bonzini
2021-10-22 15:36 ` Paolo Bonzini [this message]
2021-10-26 13:55 ` [PATCH 08/13] KVM: x86: inline kernel_pio into its sole caller Maxim Levitsky
2021-10-22 15:36 ` [PATCH 09/13] KVM: x86: move all vcpu->arch.pio* setup in emulator_pio_in_out Paolo Bonzini
2021-10-26 13:56 ` Maxim Levitsky
2021-10-22 15:36 ` [PATCH 10/13] KVM: x86: wean in-kernel PIO from vcpu->arch.pio* Paolo Bonzini
2021-10-26 13:56 ` Maxim Levitsky
2021-10-22 15:36 ` [PATCH 11/13] KVM: x86: wean fast IN from emulator_pio_in Paolo Bonzini
2021-10-26 13:56 ` Maxim Levitsky
2021-10-22 15:36 ` [PATCH 12/13] KVM: x86: de-underscorify __emulator_pio_in Paolo Bonzini
2021-10-26 13:56 ` Maxim Levitsky
2021-10-22 15:36 ` [PATCH 13/13] KVM: SEV-ES: reuse advance_sev_es_emulated_ins for OUT too Paolo Bonzini
2021-10-26 13:57 ` Maxim Levitsky
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