[PATCH v2 2/6] RISC-V: KVM: Introduce feature specific reset for SBI FWFT

[Anup Patel]

The SBI FWFT feature values must be reset upon VCPU reset so
introduce feature specific reset callback for this purpose.

Signed-off-by: Anup Patel <apa...@ventanamicro.com>
Reviewed-by: Andrew Jones <ajo...@ventanamicro.com>
---
 arch/riscv/kvm/vcpu_sbi_fwft.c | 30 ++++++++++++++++++++++++++++--
 1 file changed, 28 insertions(+), 2 deletions(-)

diff --git a/arch/riscv/kvm/vcpu_sbi_fwft.c b/arch/riscv/kvm/vcpu_sbi_fwft.c
index 164a01288b0a..5a3bad0f9330 100644
--- a/arch/riscv/kvm/vcpu_sbi_fwft.c
+++ b/arch/riscv/kvm/vcpu_sbi_fwft.c
@@ -30,6 +30,13 @@ struct kvm_sbi_fwft_feature {
         */
        bool (*supported)(struct kvm_vcpu *vcpu);
 
+       /**
+        * @reset: Reset the feature value irrespective whether feature is 
supported or not
+        *
+        * This callback is mandatory
+        */
+       void (*reset)(struct kvm_vcpu *vcpu);
+
        /**
         * @set: Set the feature value
         *
@@ -75,6 +82,13 @@ static bool 
kvm_sbi_fwft_misaligned_delegation_supported(struct kvm_vcpu *vcpu)
        return misaligned_traps_can_delegate();
 }
 
+static void kvm_sbi_fwft_reset_misaligned_delegation(struct kvm_vcpu *vcpu)
+{
+       struct kvm_vcpu_config *cfg = &vcpu->arch.cfg;
+
+       cfg->hedeleg &= ~MIS_DELEG;
+}
+
 static long kvm_sbi_fwft_set_misaligned_delegation(struct kvm_vcpu *vcpu,
                                        struct kvm_sbi_fwft_config *conf,
                                        unsigned long value)
@@ -124,6 +138,11 @@ static bool 
kvm_sbi_fwft_pointer_masking_pmlen_supported(struct kvm_vcpu *vcpu)
        return fwft->have_vs_pmlen_7 || fwft->have_vs_pmlen_16;
 }
 
+static void kvm_sbi_fwft_reset_pointer_masking_pmlen(struct kvm_vcpu *vcpu)
+{
+       vcpu->arch.cfg.henvcfg &= ~ENVCFG_PMM;
+}
+
 static long kvm_sbi_fwft_set_pointer_masking_pmlen(struct kvm_vcpu *vcpu,
                                                   struct kvm_sbi_fwft_config 
*conf,
                                                   unsigned long value)
@@ -180,6 +199,7 @@ static const struct kvm_sbi_fwft_feature features[] = {
        {
                .id = SBI_FWFT_MISALIGNED_EXC_DELEG,
                .supported = kvm_sbi_fwft_misaligned_delegation_supported,
+               .reset = kvm_sbi_fwft_reset_misaligned_delegation,
                .set = kvm_sbi_fwft_set_misaligned_delegation,
                .get = kvm_sbi_fwft_get_misaligned_delegation,
        },
@@ -187,6 +207,7 @@ static const struct kvm_sbi_fwft_feature features[] = {
        {
                .id = SBI_FWFT_POINTER_MASKING_PMLEN,
                .supported = kvm_sbi_fwft_pointer_masking_pmlen_supported,
+               .reset = kvm_sbi_fwft_reset_pointer_masking_pmlen,
                .set = kvm_sbi_fwft_set_pointer_masking_pmlen,
                .get = kvm_sbi_fwft_get_pointer_masking_pmlen,
        },
@@ -321,11 +342,16 @@ static void kvm_sbi_ext_fwft_deinit(struct kvm_vcpu *vcpu)
 
 static void kvm_sbi_ext_fwft_reset(struct kvm_vcpu *vcpu)
 {
-       int i;
        struct kvm_sbi_fwft *fwft = vcpu_to_fwft(vcpu);
+       const struct kvm_sbi_fwft_feature *feature;
+       int i;
 
-       for (i = 0; i < ARRAY_SIZE(features); i++)
+       for (i = 0; i < ARRAY_SIZE(features); i++) {
                fwft->configs[i].flags = 0;
+               feature = &features[i];
+               if (feature->reset)
+                       feature->reset(vcpu);
+       }
 }
 
 const struct kvm_vcpu_sbi_extension vcpu_sbi_ext_fwft = {
-- 
2.43.0