Commit b1728622 authored by Paul Durrant's avatar Paul Durrant Committed by Paolo Bonzini
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KVM: x86: PIT: Preserve state of speaker port data bit 



Currently the state of the speaker port (0x61) data bit (bit 1) is not
saved in the exported state (kvm_pit_state2) and hence is lost when
re-constructing guest state.

This patch removes the 'speaker_data_port' field from kvm_kpit_state and
instead tracks the state using a new KVM_PIT_FLAGS_SPEAKER_DATA_ON flag
defined in the API.

Signed-off-by: default avatarPaul Durrant <pdurrant@amazon.com>
Message-Id: <20220531124421.1427-1-pdurrant@amazon.com>
Signed-off-by: default avatarPaolo Bonzini <pbonzini@redhat.com>
parent 3dbec44d

Documentation/virt/kvm/api.rst

+3 −1
Original line number Diff line number Diff line
@@ -3007,6 +3007,8 @@ Valid flags are:: 


  /* disable PIT in HPET legacy mode */

  #define KVM_PIT_FLAGS_HPET_LEGACY     0x00000001

  /* speaker port data bit enabled */

  #define KVM_PIT_FLAGS_SPEAKER_DATA_ON 0x00000002



This IOCTL replaces the obsolete KVM_GET_PIT.

arch/x86/include/uapi/asm/kvm.h

+2 −1
Original line number Diff line number Diff line
@@ -307,6 +307,7 @@ struct kvm_pit_state { 
};



#define KVM_PIT_FLAGS_HPET_LEGACY     0x00000001

#define KVM_PIT_FLAGS_SPEAKER_DATA_ON 0x00000002



struct kvm_pit_state2 {

	struct kvm_pit_channel_state channels[3];

arch/x86/kvm/i8254.c

+7 −3
Original line number Diff line number Diff line
@@ -591,7 +591,10 @@ static int speaker_ioport_write(struct kvm_vcpu *vcpu, 
		return -EOPNOTSUPP;



	mutex_lock(&pit_state->lock);

	pit_state->speaker_data_on = (val >> 1) & 1;

	if (val & (1 << 1))

		pit_state->flags |= KVM_PIT_FLAGS_SPEAKER_DATA_ON;

	else

		pit_state->flags &= ~KVM_PIT_FLAGS_SPEAKER_DATA_ON;

	pit_set_gate(pit, 2, val & 1);

	mutex_unlock(&pit_state->lock);

	return 0;
@@ -612,8 +615,9 @@ static int speaker_ioport_read(struct kvm_vcpu *vcpu, 
	refresh_clock = ((unsigned int)ktime_to_ns(ktime_get()) >> 14) & 1;



	mutex_lock(&pit_state->lock);

	ret = ((pit_state->speaker_data_on << 1) | pit_get_gate(pit, 2) |

		(pit_get_out(pit, 2) << 5) | (refresh_clock << 4));

	ret = (!!(pit_state->flags & KVM_PIT_FLAGS_SPEAKER_DATA_ON) << 1) |

		pit_get_gate(pit, 2) | (pit_get_out(pit, 2) << 5) |

		(refresh_clock << 4);

	if (len > sizeof(ret))

		len = sizeof(ret);

	memcpy(data, (char *)&ret, len);

arch/x86/kvm/i8254.h

+0 −1
Original line number Diff line number Diff line
@@ -29,7 +29,6 @@ struct kvm_kpit_state { 
	bool is_periodic;

	s64 period; 				/* unit: ns */

	struct hrtimer timer;

	u32    speaker_data_on;



	struct mutex lock;

	atomic_t reinject;