diff mbox series

[4/5] KVM: arm64: Exclude host_fpsimd_state pointer from kvm_vcpu_arch

Message ID 20240302111935.129994-5-maz@kernel.org (mailing list archive)
State New, archived
Headers show
Series KVM: arm64: Move host-specific data out of kvm_vcpu_arch | expand

Commit Message

Marc Zyngier March 2, 2024, 11:19 a.m. UTC 
As the name of the field indicates, host_fpsimd_state is strictly
a host piece of data, and we reset this pointer on each PID change.

So let's move it where it belongs, and set it at load-time. Although
this is slightly more often, it is a well defined life-cycle which
matches other pieces of data.

Signed-off-by: Marc Zyngier <maz@kernel.org>
---
 arch/arm64/include/asm/kvm_host.h       | 2 +-
 arch/arm64/kvm/fpsimd.c                 | 3 +--
 arch/arm64/kvm/hyp/include/hyp/switch.h | 2 +-
 arch/arm64/kvm/hyp/nvhe/hyp-main.c      | 1 -
 4 files changed, 3 insertions(+), 5 deletions(-)

Comments

Mark Brown March 4, 2024, 8:45 p.m. UTC | #1 
On Sat, Mar 02, 2024 at 11:19:34AM +0000, Marc Zyngier wrote:
> As the name of the field indicates, host_fpsimd_state is strictly
> a host piece of data, and we reset this pointer on each PID change.
> 
> So let's move it where it belongs, and set it at load-time. Although
> this is slightly more often, it is a well defined life-cycle which
> matches other pieces of data.

Reviewed-by: Mark Brown <broonie@kernel.org>
diff mbox series

Patch

diff --git a/arch/arm64/include/asm/kvm_host.h b/arch/arm64/include/asm/kvm_host.h
index a3718f441e12..39b39da3e61b 100644
--- a/arch/arm64/include/asm/kvm_host.h
+++ b/arch/arm64/include/asm/kvm_host.h
@@ -505,6 +505,7 @@  struct kvm_cpu_context {
  */
 struct kvm_host_data {
 	struct kvm_cpu_context host_ctxt;
+	struct user_fpsimd_state *fpsimd_state;	/* hyp VA */
 
 	/*
 	 * host_debug_state contains the host registers which are
@@ -622,7 +623,6 @@  struct kvm_vcpu_arch {
 	struct kvm_guest_debug_arch vcpu_debug_state;
 	struct kvm_guest_debug_arch external_debug_state;
 
-	struct user_fpsimd_state *host_fpsimd_state;	/* hyp VA */
 	struct task_struct *parent_task;
 
 	/* VGIC state */
diff --git a/arch/arm64/kvm/fpsimd.c b/arch/arm64/kvm/fpsimd.c
index 8c1d0d4853df..f650e46d4bea 100644
--- a/arch/arm64/kvm/fpsimd.c
+++ b/arch/arm64/kvm/fpsimd.c
@@ -49,8 +49,6 @@  int kvm_arch_vcpu_run_map_fp(struct kvm_vcpu *vcpu)
 	if (ret)
 		return ret;
 
-	vcpu->arch.host_fpsimd_state = kern_hyp_va(fpsimd);
-
 	/*
 	 * We need to keep current's task_struct pinned until its data has been
 	 * unshared with the hypervisor to make sure it is not re-used by the
@@ -87,6 +85,7 @@  void kvm_arch_vcpu_load_fp(struct kvm_vcpu *vcpu)
 	 * FP_STATE_FREE if the flag set.
 	 */
 	vcpu->arch.fp_state = FP_STATE_HOST_OWNED;
+	*host_data_ptr(fpsimd_state) = kern_hyp_va(&current->thread.uw.fpsimd_state);
 
 	vcpu_clear_flag(vcpu, HOST_SVE_ENABLED);
 	if (read_sysreg(cpacr_el1) & CPACR_EL1_ZEN_EL0EN)
diff --git a/arch/arm64/kvm/hyp/include/hyp/switch.h b/arch/arm64/kvm/hyp/include/hyp/switch.h
index 8ae81301083f..f67d8eafc245 100644
--- a/arch/arm64/kvm/hyp/include/hyp/switch.h
+++ b/arch/arm64/kvm/hyp/include/hyp/switch.h
@@ -370,7 +370,7 @@  static bool kvm_hyp_handle_fpsimd(struct kvm_vcpu *vcpu, u64 *exit_code)
 
 	/* Write out the host state if it's in the registers */
 	if (vcpu->arch.fp_state == FP_STATE_HOST_OWNED)
-		__fpsimd_save_state(vcpu->arch.host_fpsimd_state);
+		__fpsimd_save_state(*host_data_ptr(fpsimd_state));
 
 	/* Restore the guest state */
 	if (sve_guest)
diff --git a/arch/arm64/kvm/hyp/nvhe/hyp-main.c b/arch/arm64/kvm/hyp/nvhe/hyp-main.c
index 2385fd03ed87..c5f625dc1f07 100644
--- a/arch/arm64/kvm/hyp/nvhe/hyp-main.c
+++ b/arch/arm64/kvm/hyp/nvhe/hyp-main.c
@@ -42,7 +42,6 @@  static void flush_hyp_vcpu(struct pkvm_hyp_vcpu *hyp_vcpu)
 	hyp_vcpu->vcpu.arch.fp_state	= host_vcpu->arch.fp_state;
 
 	hyp_vcpu->vcpu.arch.debug_ptr	= kern_hyp_va(host_vcpu->arch.debug_ptr);
-	hyp_vcpu->vcpu.arch.host_fpsimd_state = host_vcpu->arch.host_fpsimd_state;
 
 	hyp_vcpu->vcpu.arch.vsesr_el2	= host_vcpu->arch.vsesr_el2;