iv/linux
1
0
Fork 0
Code Issues Pull Requests Actions Packages Projects Releases Wiki Activity

KVM: arm64: Move HCRX_EL2 switch to load/put on VHE systems

Browse Source 
Although the nVHE behaviour requires HCRX_EL2 to be switched
on each switch between host and guest, there is nothing in
this register that would affect a VHE host.

It is thus possible to save/restore this register on load/put
on VHE systems, avoiding unnecessary sysreg access on the hot
path. Additionally, it avoids unnecessary traps when running
with NV.

To achieve this, simply move the read/writes to the *_common()
helpers, which are called on load/put on VHE, and more eagerly
on nVHE.

Reviewed-by: Eric Auger <eric.auger@redhat.com>
Signed-off-by: Marc Zyngier <maz@kernel.org>
Reviewed-by: Jing Zhang <jingzhangos@google.com>
Link: https://lore.kernel.org/r/20230815183903.2735724-28-maz@kernel.org
This commit is contained in:
Marc Zyngier 2023-08-15 19:39:01 +01:00
parent 0a5d28433a
commit a63cf31139
1 changed files with 6 additions and 6 deletions
Show Stats Download Patch File Download Diff File Expand all files Collapse all files

12
arch/arm64/kvm/hyp/include/hyp/switch.h
View File

@ -197,6 +197,9 @@ static inline void __activate_traps_common(struct kvm_vcpu *vcpu)
vcpu->arch.mdcr_el2_host = read_sysreg(mdcr_el2);
write_sysreg(vcpu->arch.mdcr_el2, mdcr_el2);
if (cpus_have_final_cap(ARM64_HAS_HCX))
write_sysreg_s(HCRX_GUEST_FLAGS, SYS_HCRX_EL2);
__activate_traps_hfgxtr(vcpu);
}
@ -213,6 +216,9 @@ static inline void __deactivate_traps_common(struct kvm_vcpu *vcpu)
vcpu_clear_flag(vcpu, PMUSERENR_ON_CPU);
}
if (cpus_have_final_cap(ARM64_HAS_HCX))
write_sysreg_s(HCRX_HOST_FLAGS, SYS_HCRX_EL2);
__deactivate_traps_hfgxtr(vcpu);
}
@ -227,9 +233,6 @@ static inline void ___activate_traps(struct kvm_vcpu *vcpu)
if (cpus_have_final_cap(ARM64_HAS_RAS_EXTN) && (hcr & HCR_VSE))
write_sysreg_s(vcpu->arch.vsesr_el2, SYS_VSESR_EL2);
if (cpus_have_final_cap(ARM64_HAS_HCX))
write_sysreg_s(HCRX_GUEST_FLAGS, SYS_HCRX_EL2);
}
static inline void ___deactivate_traps(struct kvm_vcpu *vcpu)
@ -244,9 +247,6 @@ static inline void ___deactivate_traps(struct kvm_vcpu *vcpu)
vcpu->arch.hcr_el2 &= ~HCR_VSE;
vcpu->arch.hcr_el2 |= read_sysreg(hcr_el2) & HCR_VSE;
}
if (cpus_have_final_cap(ARM64_HAS_HCX))
write_sysreg_s(HCRX_HOST_FLAGS, SYS_HCRX_EL2);
}
static inline bool __populate_fault_info(struct kvm_vcpu *vcpu)