From: Vladimir Murzin <vladimir.murzin@arm•com>
To: Mark Rutland <mark.rutland@arm•com>,
linux-arm-kernel@lists•infradead.org, kvmarm@lists•linux.dev
Cc: broonie@kernel•org, catalin.marinas@arm•com, james.morse@arm•com,
maz@kernel•org, oupton@kernel•org, tabba@google•com,
will@kernel•org
Subject: Re: [PATCH 03/18] KVM: arm64: pkvm: Save host FPMR in host cpu context
Date: Wed, 27 May 2026 11:29:12 +0100 [thread overview]
Message-ID: <75b2d87f-b609-4c17-9aac-df20bea73ee8@arm.com> (raw)
In-Reply-To: <20260521132556.584676-4-mark.rutland@arm.com>
On 5/21/26 14:25, Mark Rutland wrote:
> Protected KVM stores most of the host's system register state in
> kvm_host_data::host_ctxt, which is an instance of struct
> kvm_cpu_context. As kvm_cpu_context::sys_regs[] has a slot for FPMR, we
> can store the host's FPMR there.
>
> Do so, and remove kvm_host_data::fpmr.
>
> Signed-off-by: Mark Rutland <mark.rutland@arm•com>
> Cc: Catalin Marinas <catalin.marinas@arm•com>
> Cc: Fuad Tabba <tabba@google•com>
> Cc: James Morse <james.morse@arm•com>
> Cc: Marc Zyngier <maz@kernel•org>
> Cc: Mark Brown <broonie@kernel•org>
> Cc: Oliver Upton <oupton@kernel•org>
> Cc: Will Deacon <will@kernel•org>
> ---
> arch/arm64/include/asm/kvm_host.h | 3 ---
> arch/arm64/kvm/hyp/include/hyp/switch.h | 6 ++++--
> arch/arm64/kvm/hyp/nvhe/hyp-main.c | 5 +++--
> 3 files changed, 7 insertions(+), 7 deletions(-)
>
> diff --git a/arch/arm64/include/asm/kvm_host.h b/arch/arm64/include/asm/kvm_host.h
> index 65eead8362e0b..42b1c4764a4bf 100644
> --- a/arch/arm64/include/asm/kvm_host.h
> +++ b/arch/arm64/include/asm/kvm_host.h
> @@ -775,9 +775,6 @@ struct kvm_host_data {
> */
> struct cpu_sve_state *sve_state;
>
> - /* Used by pKVM only. */
> - u64 fpmr;
> -
> /* Ownership of the FP regs */
> enum {
> FP_STATE_FREE,
> diff --git a/arch/arm64/kvm/hyp/include/hyp/switch.h b/arch/arm64/kvm/hyp/include/hyp/switch.h
> index 98b2976837b11..cc4d011a2b380 100644
> --- a/arch/arm64/kvm/hyp/include/hyp/switch.h
> +++ b/arch/arm64/kvm/hyp/include/hyp/switch.h
> @@ -554,6 +554,8 @@ static inline void fpsimd_lazy_switch_to_host(struct kvm_vcpu *vcpu)
>
> static void kvm_hyp_save_fpsimd_host(struct kvm_vcpu *vcpu)
> {
> + struct kvm_cpu_context *hctxt = host_data_ptr(host_ctxt);
> +
> /*
> * Non-protected kvm relies on the host restoring its sve state.
> * Protected kvm restores the host's sve state as not to reveal that
> @@ -562,11 +564,11 @@ static void kvm_hyp_save_fpsimd_host(struct kvm_vcpu *vcpu)
> if (system_supports_sve()) {
> __hyp_sve_save_host();
> } else {
> - __fpsimd_save_state(host_data_ptr(host_ctxt.fp_regs));
> + __fpsimd_save_state(&hctxt->fp_regs);
> }
>
> if (kvm_has_fpmr(kern_hyp_va(vcpu->kvm)))
> - *host_data_ptr(fpmr) = read_sysreg_s(SYS_FPMR);
> + ctxt_sys_reg(hctxt, FPMR) = read_sysreg_s(SYS_FPMR);
> }
>
>
> diff --git a/arch/arm64/kvm/hyp/nvhe/hyp-main.c b/arch/arm64/kvm/hyp/nvhe/hyp-main.c
> index 06db299c37a89..db60f770060e5 100644
> --- a/arch/arm64/kvm/hyp/nvhe/hyp-main.c
> +++ b/arch/arm64/kvm/hyp/nvhe/hyp-main.c
> @@ -66,6 +66,7 @@ static void fpsimd_sve_flush(void)
>
> static void fpsimd_sve_sync(struct kvm_vcpu *vcpu)
> {
> + struct kvm_cpu_context *hctxt = host_data_ptr(host_ctxt);
> bool has_fpmr;
>
> if (!guest_owns_fp_regs())
> @@ -89,10 +90,10 @@ static void fpsimd_sve_sync(struct kvm_vcpu *vcpu)
> if (system_supports_sve())
> __hyp_sve_restore_host();
> else
> - __fpsimd_restore_state(host_data_ptr(host_ctxt.fp_regs));
> + __fpsimd_restore_state(&hctxt->fp_regs);
>
> if (has_fpmr)
> - write_sysreg_s(*host_data_ptr(fpmr), SYS_FPMR);
> + write_sysreg_s(ctxt_sys_reg(hctxt, FPMR), SYS_FPMR);
>
> *host_data_ptr(fp_owner) = FP_STATE_HOST_OWNED;
> }
> -- 2.30.2
>
FWIW,
Reviewed-by: Vladimir Murzin <vladimir.murzin@arm•com>
next prev parent reply other threads:[~2026-05-27 10:44 UTC|newest]
Thread overview: 78+ messages / expand[flat|nested] mbox.gz Atom feed top
2026-05-21 13:25 [PATCH 00/18] arm64+KVM: FPSIMD/SVE/SME cleanups Mark Rutland
2026-05-21 13:25 ` [PATCH 01/18] KVM: arm64: Don't include <asm/fpsimdmacros.h> Mark Rutland
2026-05-26 14:18 ` Mark Brown
2026-05-27 10:10 ` Vladimir Murzin
2026-05-21 13:25 ` [PATCH 02/18] KVM: arm64: Don't override FFR save/restore argument Mark Rutland
2026-05-26 14:27 ` Mark Brown
2026-05-27 10:16 ` Vladimir Murzin
2026-05-21 13:25 ` [PATCH 03/18] KVM: arm64: pkvm: Save host FPMR in host cpu context Mark Rutland
2026-05-27 10:29 ` Vladimir Murzin [this message]
2026-05-21 13:25 ` [PATCH 04/18] KVM: arm64: pkvm: Remove struct cpu_sve_state Mark Rutland
2026-05-27 11:58 ` Vladimir Murzin
2026-05-27 16:02 ` Mark Rutland
2026-05-27 16:11 ` Vladimir Murzin
2026-05-28 15:09 ` Mark Rutland
2026-05-28 15:12 ` Vladimir Murzin
2026-05-21 13:25 ` [PATCH 05/18] arm64: fpsimd: Fold sve_init_regs() into do_sve_acc() Mark Rutland
2026-05-26 15:28 ` Mark Brown
2026-05-27 12:05 ` Vladimir Murzin
2026-05-21 13:25 ` [PATCH 06/18] arm64: fpsimd: Remove sve_set_vq() and sme_set_vq() Mark Rutland
2026-05-26 15:42 ` Mark Brown
2026-05-27 12:50 ` Vladimir Murzin
2026-05-21 13:25 ` [PATCH 07/18] arm64: fpsimd: Use assembler for SVE instructions Mark Rutland
2026-05-26 15:43 ` Mark Brown
2026-05-27 12:58 ` Vladimir Murzin
2026-05-27 16:10 ` Mark Rutland
2026-05-21 13:25 ` [PATCH 08/18] arm64: fpsimd: Use assembler for baseline SME instructions Mark Rutland
2026-05-26 15:45 ` Mark Brown
2026-05-27 13:06 ` Vladimir Murzin
2026-05-21 13:25 ` [PATCH 09/18] arm64: fpsimd: Move sve_get_vl() and sme_get_vl() inline Mark Rutland
2026-05-26 15:47 ` Mark Brown
2026-05-27 13:18 ` Vladimir Murzin
2026-05-21 13:25 ` [PATCH 10/18] arm64: sysreg: Add FPCR and FPSR Mark Rutland
2026-05-26 15:55 ` Mark Brown
2026-05-26 16:51 ` Mark Rutland
2026-05-26 16:54 ` Mark Brown
2026-05-21 13:25 ` [PATCH 11/18] arm64: fpsimd: Split FPSR/FPCR from SVE save/restore Mark Rutland
2026-05-26 16:28 ` Mark Brown
2026-05-27 13:51 ` Mark Rutland
2026-05-27 14:13 ` Mark Brown
2026-05-27 16:13 ` Mark Rutland
2026-05-27 13:44 ` Vladimir Murzin
2026-05-21 13:25 ` [PATCH 12/18] arm64: fpsimd: Move fpsimd save/restore inline Mark Rutland
2026-05-26 16:44 ` Mark Brown
2026-05-28 16:15 ` Mark Rutland
2026-05-28 16:39 ` Mark Brown
2026-05-27 14:49 ` Vladimir Murzin
2026-05-27 15:34 ` Mark Rutland
2026-05-27 16:13 ` Vladimir Murzin
2026-05-21 13:25 ` [PATCH 13/18] arm64: fpsimd: Use opaque type for SVE state Mark Rutland
2026-05-26 16:53 ` Mark Brown
2026-05-28 9:45 ` Vladimir Murzin
2026-05-28 16:25 ` Mark Rutland
2026-05-21 13:25 ` [PATCH 14/18] arm64: fpsimd: Use opaque type for SME state Mark Rutland
2026-05-26 16:56 ` Mark Brown
2026-05-28 9:51 ` Vladimir Murzin
2026-05-21 13:25 ` [PATCH 15/18] arm64: fpsimd: Move SVE save/restore inline Mark Rutland
2026-05-27 12:29 ` Mark Brown
2026-05-28 10:39 ` Vladimir Murzin
2026-05-21 13:25 ` [PATCH 16/18] arm64: fpsimd: Move sve_flush_live() inline Mark Rutland
2026-05-27 12:54 ` Mark Brown
2026-05-27 16:23 ` Mark Rutland
2026-05-28 10:49 ` Vladimir Murzin
2026-05-21 13:25 ` [PATCH 17/18] arm64: fpsimd: Move SME save/restore inline Mark Rutland
2026-05-26 14:08 ` Mark Rutland
2026-05-26 14:39 ` Vladimir Murzin
2026-05-26 15:28 ` Mark Rutland
2026-05-26 16:38 ` Mark Rutland
2026-05-27 9:00 ` Vladimir Murzin
2026-05-29 9:10 ` Mark Rutland
2026-05-28 12:30 ` Vladimir Murzin
2026-05-28 14:39 ` Mark Rutland
2026-05-21 13:25 ` [PATCH 18/18] arm64: fpsimd: Remove <asm/fpsimdmacros.h> Mark Rutland
2026-05-28 13:10 ` Vladimir Murzin
2026-05-27 8:07 ` [PATCH 00/18] arm64+KVM: FPSIMD/SVE/SME cleanups Marc Zyngier
2026-05-27 10:32 ` Mark Rutland
2026-05-27 14:36 ` Will Deacon
2026-05-28 13:21 ` Vladimir Murzin
2026-05-28 16:28 ` Mark Rutland
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