[PATCH 09/12] KVM: arm64: Honor guest requested traps in GICv3 emulation

Marc Zyngier
2024-08-20T10:06:19Z

On platforms that require emulation of the CPU interface, we still
need to honor the traps requested by the guest (ICH_HCR_EL2 as well
as the FGTs for ICC_IGRPEN{0,1}_EL1.

Check for these bits early and lail out if any trap applies.

Signed-off-by: Marc Zyngier <maz@kernel.org>
---
arch/arm64/kvm/hyp/vgic-v3-sr.c | 72 +++++++++++++++++++++++++++++++++
1 file changed, 72 insertions(+)

diff --git a/arch/arm64/kvm/hyp/vgic-v3-sr.c b/arch/arm64/kvm/hyp/vgic-v3-sr.c
index a184def8f5ad..a01138a663ae 100644
--- a/arch/arm64/kvm/hyp/vgic-v3-sr.c
+++ b/arch/arm64/kvm/hyp/vgic-v3-sr.c
@@ -1042,6 +1042,75 @@ static void __vgic_v3_write_ctlr(struct kvm_vcpu *vcpu, u32 vmcr, int rt)
write_gicreg(vmcr, ICH_VMCR_EL2);
}

+static bool __vgic_v3_check_trap_forwarding(struct kvm_vcpu *vcpu,
+ u32 sysreg, bool is_read)
+{
+ u64 ich_hcr;
+
+ if (!vcpu_has_nv(vcpu) || is_hyp_ctxt(vcpu))
+ return false;
+
+ ich_hcr = __vcpu_sys_reg(vcpu, ICH_HCR_EL2);
+
+ switch (sysreg) {
+ case SYS_ICC_IGRPEN0_EL1:
+ if (is_read &&
+ (__vcpu_sys_reg(vcpu, HFGRTR_EL2) & HFGxTR_EL2_ICC_IGRPENn_EL1))
+ return true;
+
+ if (!is_read &&
+ (__vcpu_sys_reg(vcpu, HFGWTR_EL2) & HFGxTR_EL2_ICC_IGRPENn_EL1))
+ return true;
+
+ fallthrough;
+
+ case SYS_ICC_AP0Rn_EL1(0):
+ case SYS_ICC_AP0Rn_EL1(1):
+ case SYS_ICC_AP0Rn_EL1(2):
+ case SYS_ICC_AP0Rn_EL1(3):
+ case SYS_ICC_BPR0_EL1:
+ case SYS_ICC_EOIR0_EL1:
+ case SYS_ICC_HPPIR0_EL1:
+ case SYS_ICC_IAR0_EL1:
+ return ich_hcr & ICH_HCR_TALL0;
+
+ case SYS_ICC_IGRPEN1_EL1:
+ if (is_read &&
+ (__vcpu_sys_reg(vcpu, HFGRTR_EL2) & HFGxTR_EL2_ICC_IGRPENn_EL1))
+ return true;
+
+ if (!is_read &&
+ (__vcpu_sys_reg(vcpu, HFGWTR_EL2) & HFGxTR_EL2_ICC_IGRPENn_EL1))
+ return true;
+
+ fallthrough;
+
+ case SYS_ICC_AP1Rn_EL1(0):
+ case SYS_ICC_AP1Rn_EL1(1):
+ case SYS_ICC_AP1Rn_EL1(2):
+ case SYS_ICC_AP1Rn_EL1(3):
+ case SYS_ICC_BPR1_EL1:
+ case SYS_ICC_EOIR1_EL1:
+ case SYS_ICC_HPPIR1_EL1:
+ case SYS_ICC_IAR1_EL1:
+ return ich_hcr & ICH_HCR_TALL1;
+
+ case SYS_ICC_DIR_EL1:
+ if (ich_hcr & ICH_HCR_TDIR)
+ return true;
+
+ fallthrough;
+
+ case SYS_ICC_RPR_EL1:
+ case SYS_ICC_CTLR_EL1:
+ case SYS_ICC_PMR_EL1:
+ return ich_hcr & ICH_HCR_TC;
+
+ default:
+ return false;
+ }
+}
+
int __vgic_v3_perform_cpuif_access(struct kvm_vcpu *vcpu)
{
int rt;
@@ -1065,6 +1134,9 @@ int __vgic_v3_perform_cpuif_access(struct kvm_vcpu *vcpu)

is_read = (esr & ESR_ELx_SYS64_ISS_DIR_MASK) == ESR_ELx_SYS64_ISS_DIR_READ;

+ if (__vgic_v3_check_trap_forwarding(vcpu, sysreg, is_read))
+ return 0;
+
switch (sysreg) {
case SYS_ICC_IAR0_EL1:
case SYS_ICC_IAR1_EL1:
--
2.39.2