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KVM: x86: move all vcpu->arch.pio* setup in emulator_pio_in_out()

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For now, this is basically an excuse to add back the void* argument to
the function, while removing some knowledge of vcpu->arch.pio* from
its callers.  The WARN that vcpu->arch.pio.count is zero is also
extended to OUT operations.

The vcpu->arch.pio* fields still need to be filled even when the PIO is
handled in-kernel as __emulator_pio_in() is always followed by
complete_emulator_pio_in().  But after fixing that, it will be possible to
to only populate the vcpu->arch.pio* fields on userspace exits.

No functional change intended.

Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
This commit is contained in:
Paolo Bonzini 2021-10-22 08:07:19 -04:00
parent 35ab3b77a0
commit 30d583fd4e
2 changed files with 14 additions and 9 deletions
Download patch file Download diff file Expand all files Collapse all files

2
arch/x86/kvm/trace.h
View file

@ -154,7 +154,7 @@ TRACE_EVENT(kvm_xen_hypercall,
TRACE_EVENT(kvm_pio,
TP_PROTO(unsigned int rw, unsigned int port, unsigned int size,
unsigned int count, void *data),
unsigned int count, const void *data),
TP_ARGS(rw, port, size, count, data),
TP_STRUCT__entry(

21
arch/x86/kvm/x86.c
View file

@ -7576,17 +7576,25 @@ emul_write:
}
static int emulator_pio_in_out(struct kvm_vcpu *vcpu, int size,
unsigned short port,
unsigned short port, void *data,
unsigned int count, bool in)
{
void *data = vcpu->arch.pio_data;
unsigned i;
int r;
WARN_ON_ONCE(vcpu->arch.pio.count);
vcpu->arch.pio.port = port;
vcpu->arch.pio.in = in;
vcpu->arch.pio.count = count;
vcpu->arch.pio.size = size;
if (in) {
/* The buffer is only used in complete_emulator_pio_in(). */
WARN_ON(data);
memset(vcpu->arch.pio_data, 0, size * count);
} else {
memcpy(vcpu->arch.pio_data, data, size * count);
}
data = vcpu->arch.pio_data;
for (i = 0; i < count; i++) {
if (in)
@ -7623,9 +7631,7 @@ userspace_io:
static int __emulator_pio_in(struct kvm_vcpu *vcpu, int size,
unsigned short port, unsigned int count)
{
WARN_ON(vcpu->arch.pio.count);
memset(vcpu->arch.pio_data, 0, size * count);
return emulator_pio_in_out(vcpu, size, port, count, true);
return emulator_pio_in_out(vcpu, size, port, NULL, count, true);
}
static void complete_emulator_pio_in(struct kvm_vcpu *vcpu, void *val)
@ -7674,9 +7680,8 @@ static int emulator_pio_out(struct kvm_vcpu *vcpu, int size,
{
int ret;
memcpy(vcpu->arch.pio_data, val, size * count);
trace_kvm_pio(KVM_PIO_OUT, port, size, count, vcpu->arch.pio_data);
ret = emulator_pio_in_out(vcpu, size, port, count, false);
trace_kvm_pio(KVM_PIO_OUT, port, size, count, val);
ret = emulator_pio_in_out(vcpu, size, port, (void *)val, count, false);
if (ret)
vcpu->arch.pio.count = 0;