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: Paul Durrant <pdurrant@amazon.com>
Message-Id: <20220531124421.1427-1-pdurrant@amazon.com>
Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>

diff --git a/Documentation/virt/kvm/api.rst b/Documentation/virt/kvm/api.rst
index 30e31a886422444e44f7871ae4d58abb5f3c117a..9cbbfdb663b63f3dbc66415e98c14a089072f8fa 100644 (file)
--- a/Documentation/virt/kvm/api.rst
+++ b/Documentation/virt/kvm/api.rst
@@ -3006,7 +3006,9 @@ KVM_CREATE_PIT2. The state is returned in the following structure::
 Valid flags are::
 
   /* disable PIT in HPET legacy mode */
-  #define KVM_PIT_FLAGS_HPET_LEGACY  0x00000001
+  #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.
 

diff --git a/arch/x86/include/uapi/asm/kvm.h b/arch/x86/include/uapi/asm/kvm.h
index 24c807c8d5f7a828e7b9b472c80c48e7514a0f96..50a4e787d5e6e2580603380816c0c523c511d4f8 100644 (file)
--- a/arch/x86/include/uapi/asm/kvm.h
+++ b/arch/x86/include/uapi/asm/kvm.h
@@ -306,7 +306,8 @@ struct kvm_pit_state {
        struct kvm_pit_channel_state channels[3];
 };
 
-#define KVM_PIT_FLAGS_HPET_LEGACY  0x00000001
+#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];

diff --git a/arch/x86/kvm/i8254.c b/arch/x86/kvm/i8254.c
index 1c83076091af3810ce3243312cb7b553bb587c6d..e0a7a0e7a73c9afd89a3e57660acf2ae83b1beae 100644 (file)
--- a/arch/x86/kvm/i8254.c
+++ b/arch/x86/kvm/i8254.c
@@ -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);

diff --git a/arch/x86/kvm/i8254.h b/arch/x86/kvm/i8254.h
index 394d9527da7ee904dbd262626c3fd8575de58706..a768212ba821c1d27bbff57f85867dbbd092a951 100644 (file)
--- a/arch/x86/kvm/i8254.h
+++ b/arch/x86/kvm/i8254.h
@@ -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;