5.15-stable review patch. If anyone has any objections, please let me know.
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From: Mark Rutland mark.rutland@arm.com
[ Upstream commit 8eca7f6d5100b6997df4f532090bc3f7e0203bef ]
Now that the host eagerly saves its own FPSIMD/SVE/SME state, non-protected KVM never needs to save the host FPSIMD/SVE/SME state, and the code to do this is never used. Protected KVM still needs to save/restore the host FPSIMD/SVE state to avoid leaking guest state to the host (and to avoid revealing to the host whether the guest used FPSIMD/SVE/SME), and that code needs to be retained.
Remove the unused code and data structures.
To avoid the need for a stub copy of kvm_hyp_save_fpsimd_host() in the VHE hyp code, the nVHE/hVHE version is moved into the shared switch header, where it is only invoked when KVM is in protected mode.
Signed-off-by: Mark Rutland mark.rutland@arm.com Reviewed-by: Mark Brown broonie@kernel.org Tested-by: Mark Brown broonie@kernel.org Acked-by: Will Deacon will@kernel.org Cc: Catalin Marinas catalin.marinas@arm.com Cc: Fuad Tabba tabba@google.com Cc: Marc Zyngier maz@kernel.org Cc: Oliver Upton oliver.upton@linux.dev Reviewed-by: Oliver Upton oliver.upton@linux.dev Link: https://lore.kernel.org/r/20250210195226.1215254-3-mark.rutland@arm.com Signed-off-by: Marc Zyngier maz@kernel.org Signed-off-by: Mark Brown broonie@kernel.org Signed-off-by: Greg Kroah-Hartman gregkh@linuxfoundation.org --- arch/arm64/include/asm/kvm_host.h | 1 - arch/arm64/kvm/fpsimd.c | 1 - arch/arm64/kvm/hyp/include/hyp/switch.h | 6 +----- 3 files changed, 1 insertion(+), 7 deletions(-)
--- a/arch/arm64/include/asm/kvm_host.h +++ b/arch/arm64/include/asm/kvm_host.h @@ -333,7 +333,6 @@ struct kvm_vcpu_arch { struct kvm_guest_debug_arch external_debug_state;
struct thread_info *host_thread_info; /* hyp VA */ - struct user_fpsimd_state *host_fpsimd_state; /* hyp VA */
struct { /* {Break,watch}point registers */ --- a/arch/arm64/kvm/fpsimd.c +++ b/arch/arm64/kvm/fpsimd.c @@ -55,7 +55,6 @@ int kvm_arch_vcpu_run_map_fp(struct kvm_ }
vcpu->arch.host_thread_info = kern_hyp_va(ti); - vcpu->arch.host_fpsimd_state = kern_hyp_va(fpsimd); error: return ret; } --- a/arch/arm64/kvm/hyp/include/hyp/switch.h +++ b/arch/arm64/kvm/hyp/include/hyp/switch.h @@ -251,11 +251,7 @@ static inline bool __hyp_handle_fpsimd(s } isb();
- if (vcpu->arch.flags & KVM_ARM64_FP_HOST) { - __fpsimd_save_state(vcpu->arch.host_fpsimd_state); - vcpu->arch.flags &= ~KVM_ARM64_FP_HOST; - } - + /* Restore the guest state */ if (sve_guest) __hyp_sve_restore_guest(vcpu); else