[PATCH 03/18] KVM: arm64: pkvm: Save host FPMR in host cpu context
Mark Rutland
mark.rutland at arm.com
Thu May 21 06:25:41 PDT 2026
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 at arm.com>
Cc: Catalin Marinas <catalin.marinas at arm.com>
Cc: Fuad Tabba <tabba at google.com>
Cc: James Morse <james.morse at arm.com>
Cc: Marc Zyngier <maz at kernel.org>
Cc: Mark Brown <broonie at kernel.org>
Cc: Oliver Upton <oupton at kernel.org>
Cc: Will Deacon <will at 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
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