Merge branch kvm-arm64/host_data into kvmarm-master/next

* kvm-arm64/host_data:
  : .
  : Rationalise the host-specific data to live as part of the per-CPU state.
  :
  : From the cover letter:
  :
  : "It appears that over the years, we have accumulated a lot of cruft in
  : the kvm_vcpu_arch structure. Part of the gunk is data that is strictly
  : host CPU specific, and this result in two main problems:
  :
  : - the structure itself is stupidly large, over 8kB. With the
  :   arch-agnostic kvm_vcpu, we're above 10kB, which is insane. This has
  :   some ripple effects, as we need physically contiguous allocation to
  :   be able to map it at EL2 for !VHE. There is more to it though, as
  :   some data structures, although per-vcpu, could be allocated
  :   separately.
  :
  : - We lose track of the life-cycle of this data, because we're
  :   guaranteed that it will be around forever and we start relying on
  :   wrong assumptions. This is becoming a maintenance burden.
  :
  : This series rectifies some of these things, starting with the two main
  : offenders: debug and FP, a lot of which gets pushed out to the per-CPU
  : host structure. Indeed, their lifetime really isn't that of the vcpu,
  : but tied to the physical CPU the vpcu runs on.
  :
  : This results in a small reduction of the vcpu size, but mainly a much
  : clearer understanding of the life-cycle of these structures."
  : .
  KVM: arm64: Move management of __hyp_running_vcpu to load/put on VHE
  KVM: arm64: Exclude FP ownership from kvm_vcpu_arch
  KVM: arm64: Exclude host_fpsimd_state pointer from kvm_vcpu_arch
  KVM: arm64: Exclude mdcr_el2_host from kvm_vcpu_arch
  KVM: arm64: Exclude host_debug_data from vcpu_arch
  KVM: arm64: Add accessor for per-CPU state

Signed-off-by: Marc Zyngier <maz@kernel.org>

9 files changed, 32 insertions, 33 deletions

diff --git a/arch/arm64/kvm/hyp/include/hyp/debug-sr.h b/arch/arm64/kvm/hyp/include/hyp/debug-sr.h
index 961bbef104a6..d00093699aaf 100644
--- a/arch/arm64/kvm/hyp/include/hyp/debug-sr.h
+++ b/arch/arm64/kvm/hyp/include/hyp/debug-sr.h
@@ -135,9 +135,9 @@ static inline void __debug_switch_to_guest_common(struct kvm_vcpu *vcpu)
 	if (!vcpu_get_flag(vcpu, DEBUG_DIRTY))
 		return;
 
-	host_ctxt = &this_cpu_ptr(&kvm_host_data)->host_ctxt;
+	host_ctxt = host_data_ptr(host_ctxt);
 	guest_ctxt = &vcpu->arch.ctxt;
-	host_dbg = &vcpu->arch.host_debug_state.regs;
+	host_dbg = host_data_ptr(host_debug_state.regs);
 	guest_dbg = kern_hyp_va(vcpu->arch.debug_ptr);
 
 	__debug_save_state(host_dbg, host_ctxt);
@@ -154,9 +154,9 @@ static inline void __debug_switch_to_host_common(struct kvm_vcpu *vcpu)
 	if (!vcpu_get_flag(vcpu, DEBUG_DIRTY))
 		return;
 
-	host_ctxt = &this_cpu_ptr(&kvm_host_data)->host_ctxt;
+	host_ctxt = host_data_ptr(host_ctxt);
 	guest_ctxt = &vcpu->arch.ctxt;
-	host_dbg = &vcpu->arch.host_debug_state.regs;
+	host_dbg = host_data_ptr(host_debug_state.regs);
 	guest_dbg = kern_hyp_va(vcpu->arch.debug_ptr);
 
 	__debug_save_state(guest_dbg, guest_ctxt);
diff --git a/arch/arm64/kvm/hyp/include/hyp/switch.h b/arch/arm64/kvm/hyp/include/hyp/switch.h
index e3fcf8c4d5b4..2629420d0659 100644
--- a/arch/arm64/kvm/hyp/include/hyp/switch.h
+++ b/arch/arm64/kvm/hyp/include/hyp/switch.h
@@ -42,7 +42,7 @@ extern struct kvm_exception_table_entry __stop___kvm_ex_table;
 /* Check whether the FP regs are owned by the guest */
 static inline bool guest_owns_fp_regs(struct kvm_vcpu *vcpu)
 {
-	return vcpu->arch.fp_state == FP_STATE_GUEST_OWNED;
+	return *host_data_ptr(fp_owner) == FP_STATE_GUEST_OWNED;
 }
 
 /* Save the 32-bit only FPSIMD system register state */
@@ -155,7 +155,7 @@ static inline bool cpu_has_amu(void)
 
 static inline void __activate_traps_hfgxtr(struct kvm_vcpu *vcpu)
 {
-	struct kvm_cpu_context *hctxt = &this_cpu_ptr(&kvm_host_data)->host_ctxt;
+	struct kvm_cpu_context *hctxt = host_data_ptr(host_ctxt);
 	struct kvm *kvm = kern_hyp_va(vcpu->kvm);
 
 	CHECK_FGT_MASKS(HFGRTR_EL2);
@@ -191,7 +191,7 @@ static inline void __activate_traps_hfgxtr(struct kvm_vcpu *vcpu)
 
 static inline void __deactivate_traps_hfgxtr(struct kvm_vcpu *vcpu)
 {
-	struct kvm_cpu_context *hctxt = &this_cpu_ptr(&kvm_host_data)->host_ctxt;
+	struct kvm_cpu_context *hctxt = host_data_ptr(host_ctxt);
 	struct kvm *kvm = kern_hyp_va(vcpu->kvm);
 
 	if (!cpus_have_final_cap(ARM64_HAS_FGT))
@@ -226,13 +226,13 @@ static inline void __activate_traps_common(struct kvm_vcpu *vcpu)
 
 		write_sysreg(0, pmselr_el0);
 
-		hctxt = &this_cpu_ptr(&kvm_host_data)->host_ctxt;
+		hctxt = host_data_ptr(host_ctxt);
 		ctxt_sys_reg(hctxt, PMUSERENR_EL0) = read_sysreg(pmuserenr_el0);
 		write_sysreg(ARMV8_PMU_USERENR_MASK, pmuserenr_el0);
 		vcpu_set_flag(vcpu, PMUSERENR_ON_CPU);
 	}
 
-	vcpu->arch.mdcr_el2_host = read_sysreg(mdcr_el2);
+	*host_data_ptr(host_debug_state.mdcr_el2) = read_sysreg(mdcr_el2);
 	write_sysreg(vcpu->arch.mdcr_el2, mdcr_el2);
 
 	if (cpus_have_final_cap(ARM64_HAS_HCX)) {
@@ -254,13 +254,13 @@ static inline void __activate_traps_common(struct kvm_vcpu *vcpu)
 
 static inline void __deactivate_traps_common(struct kvm_vcpu *vcpu)
 {
-	write_sysreg(vcpu->arch.mdcr_el2_host, mdcr_el2);
+	write_sysreg(*host_data_ptr(host_debug_state.mdcr_el2), mdcr_el2);
 
 	write_sysreg(0, hstr_el2);
 	if (kvm_arm_support_pmu_v3()) {
 		struct kvm_cpu_context *hctxt;
 
-		hctxt = &this_cpu_ptr(&kvm_host_data)->host_ctxt;
+		hctxt = host_data_ptr(host_ctxt);
 		write_sysreg(ctxt_sys_reg(hctxt, PMUSERENR_EL0), pmuserenr_el0);
 		vcpu_clear_flag(vcpu, PMUSERENR_ON_CPU);
 	}
@@ -376,8 +376,8 @@ static bool kvm_hyp_handle_fpsimd(struct kvm_vcpu *vcpu, u64 *exit_code)
 	isb();
 
 	/* 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);
+	if (*host_data_ptr(fp_owner) == FP_STATE_HOST_OWNED)
+		__fpsimd_save_state(*host_data_ptr(fpsimd_state));
 
 	/* Restore the guest state */
 	if (sve_guest)
@@ -389,7 +389,7 @@ static bool kvm_hyp_handle_fpsimd(struct kvm_vcpu *vcpu, u64 *exit_code)
 	if (!(read_sysreg(hcr_el2) & HCR_RW))
 		write_sysreg(__vcpu_sys_reg(vcpu, FPEXC32_EL2), fpexc32_el2);
 
-	vcpu->arch.fp_state = FP_STATE_GUEST_OWNED;
+	*host_data_ptr(fp_owner) = FP_STATE_GUEST_OWNED;
 
 	return true;
 }
diff --git a/arch/arm64/kvm/hyp/nvhe/debug-sr.c b/arch/arm64/kvm/hyp/nvhe/debug-sr.c
index 7746ea507b6f..53efda0235cf 100644
--- a/arch/arm64/kvm/hyp/nvhe/debug-sr.c
+++ b/arch/arm64/kvm/hyp/nvhe/debug-sr.c
@@ -83,10 +83,10 @@ void __debug_save_host_buffers_nvhe(struct kvm_vcpu *vcpu)
 {
 	/* Disable and flush SPE data generation */
 	if (vcpu_get_flag(vcpu, DEBUG_STATE_SAVE_SPE))
-		__debug_save_spe(&vcpu->arch.host_debug_state.pmscr_el1);
+		__debug_save_spe(host_data_ptr(host_debug_state.pmscr_el1));
 	/* Disable and flush Self-Hosted Trace generation */
 	if (vcpu_get_flag(vcpu, DEBUG_STATE_SAVE_TRBE))
-		__debug_save_trace(&vcpu->arch.host_debug_state.trfcr_el1);
+		__debug_save_trace(host_data_ptr(host_debug_state.trfcr_el1));
 }
 
 void __debug_switch_to_guest(struct kvm_vcpu *vcpu)
@@ -97,9 +97,9 @@ void __debug_switch_to_guest(struct kvm_vcpu *vcpu)
 void __debug_restore_host_buffers_nvhe(struct kvm_vcpu *vcpu)
 {
 	if (vcpu_get_flag(vcpu, DEBUG_STATE_SAVE_SPE))
-		__debug_restore_spe(vcpu->arch.host_debug_state.pmscr_el1);
+		__debug_restore_spe(*host_data_ptr(host_debug_state.pmscr_el1));
 	if (vcpu_get_flag(vcpu, DEBUG_STATE_SAVE_TRBE))
-		__debug_restore_trace(vcpu->arch.host_debug_state.trfcr_el1);
+		__debug_restore_trace(*host_data_ptr(host_debug_state.trfcr_el1));
 }
 
 void __debug_switch_to_host(struct kvm_vcpu *vcpu)
diff --git a/arch/arm64/kvm/hyp/nvhe/hyp-main.c b/arch/arm64/kvm/hyp/nvhe/hyp-main.c
index 2385fd03ed87..26561c562f7a 100644
--- a/arch/arm64/kvm/hyp/nvhe/hyp-main.c
+++ b/arch/arm64/kvm/hyp/nvhe/hyp-main.c
@@ -39,10 +39,8 @@ static void flush_hyp_vcpu(struct pkvm_hyp_vcpu *hyp_vcpu)
 	hyp_vcpu->vcpu.arch.cptr_el2	= host_vcpu->arch.cptr_el2;
 
 	hyp_vcpu->vcpu.arch.iflags	= host_vcpu->arch.iflags;
-	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;
 
@@ -64,7 +62,6 @@ static void sync_hyp_vcpu(struct pkvm_hyp_vcpu *hyp_vcpu)
 	host_vcpu->arch.fault		= hyp_vcpu->vcpu.arch.fault;
 
 	host_vcpu->arch.iflags		= hyp_vcpu->vcpu.arch.iflags;
-	host_vcpu->arch.fp_state	= hyp_vcpu->vcpu.arch.fp_state;
 
 	host_cpu_if->vgic_hcr		= hyp_cpu_if->vgic_hcr;
 	for (i = 0; i < hyp_cpu_if->used_lrs; ++i)
diff --git a/arch/arm64/kvm/hyp/nvhe/psci-relay.c b/arch/arm64/kvm/hyp/nvhe/psci-relay.c
index d57bcb6ab94d..dfe8fe0f7eaf 100644
--- a/arch/arm64/kvm/hyp/nvhe/psci-relay.c
+++ b/arch/arm64/kvm/hyp/nvhe/psci-relay.c
@@ -205,7 +205,7 @@ asmlinkage void __noreturn __kvm_host_psci_cpu_entry(bool is_cpu_on)
 	struct psci_boot_args *boot_args;
 	struct kvm_cpu_context *host_ctxt;
 
-	host_ctxt = &this_cpu_ptr(&kvm_host_data)->host_ctxt;
+	host_ctxt = host_data_ptr(host_ctxt);
 
 	if (is_cpu_on)
 		boot_args = this_cpu_ptr(&cpu_on_args);
diff --git a/arch/arm64/kvm/hyp/nvhe/setup.c b/arch/arm64/kvm/hyp/nvhe/setup.c
index bc58d1b515af..ae00dfa80801 100644
--- a/arch/arm64/kvm/hyp/nvhe/setup.c
+++ b/arch/arm64/kvm/hyp/nvhe/setup.c
@@ -257,8 +257,7 @@ static int fix_hyp_pgtable_refcnt(void)
 
 void __noreturn __pkvm_init_finalise(void)
 {
-	struct kvm_host_data *host_data = this_cpu_ptr(&kvm_host_data);
-	struct kvm_cpu_context *host_ctxt = &host_data->host_ctxt;
+	struct kvm_cpu_context *host_ctxt = host_data_ptr(host_ctxt);
 	unsigned long nr_pages, reserved_pages, pfn;
 	int ret;
 
diff --git a/arch/arm64/kvm/hyp/nvhe/switch.c b/arch/arm64/kvm/hyp/nvhe/switch.c
index c50f8459e4fc..1f82d531a494 100644
--- a/arch/arm64/kvm/hyp/nvhe/switch.c
+++ b/arch/arm64/kvm/hyp/nvhe/switch.c
@@ -264,7 +264,7 @@ int __kvm_vcpu_run(struct kvm_vcpu *vcpu)
 		pmr_sync();
 	}
 
-	host_ctxt = &this_cpu_ptr(&kvm_host_data)->host_ctxt;
+	host_ctxt = host_data_ptr(host_ctxt);
 	host_ctxt->__hyp_running_vcpu = vcpu;
 	guest_ctxt = &vcpu->arch.ctxt;
 
@@ -337,7 +337,7 @@ int __kvm_vcpu_run(struct kvm_vcpu *vcpu)
 
 	__sysreg_restore_state_nvhe(host_ctxt);
 
-	if (vcpu->arch.fp_state == FP_STATE_GUEST_OWNED)
+	if (*host_data_ptr(fp_owner) == FP_STATE_GUEST_OWNED)
 		__fpsimd_save_fpexc32(vcpu);
 
 	__debug_switch_to_host(vcpu);
@@ -367,7 +367,7 @@ asmlinkage void __noreturn hyp_panic(void)
 	struct kvm_cpu_context *host_ctxt;
 	struct kvm_vcpu *vcpu;
 
-	host_ctxt = &this_cpu_ptr(&kvm_host_data)->host_ctxt;
+	host_ctxt = host_data_ptr(host_ctxt);
 	vcpu = host_ctxt->__hyp_running_vcpu;
 
 	if (vcpu) {
diff --git a/arch/arm64/kvm/hyp/vhe/switch.c b/arch/arm64/kvm/hyp/vhe/switch.c
index 1581df6aec87..0027cc9b985e 100644
--- a/arch/arm64/kvm/hyp/vhe/switch.c
+++ b/arch/arm64/kvm/hyp/vhe/switch.c
@@ -162,6 +162,8 @@ static void __vcpu_put_deactivate_traps(struct kvm_vcpu *vcpu)
 
 void kvm_vcpu_load_vhe(struct kvm_vcpu *vcpu)
 {
+	host_data_ptr(host_ctxt)->__hyp_running_vcpu = vcpu;
+
 	__vcpu_load_switch_sysregs(vcpu);
 	__vcpu_load_activate_traps(vcpu);
 	__load_stage2(vcpu->arch.hw_mmu, vcpu->arch.hw_mmu->arch);
@@ -171,6 +173,8 @@ void kvm_vcpu_put_vhe(struct kvm_vcpu *vcpu)
 {
 	__vcpu_put_deactivate_traps(vcpu);
 	__vcpu_put_switch_sysregs(vcpu);
+
+	host_data_ptr(host_ctxt)->__hyp_running_vcpu = NULL;
 }
 
 static const exit_handler_fn hyp_exit_handlers[] = {
@@ -221,8 +225,7 @@ static int __kvm_vcpu_run_vhe(struct kvm_vcpu *vcpu)
 	struct kvm_cpu_context *guest_ctxt;
 	u64 exit_code;
 
-	host_ctxt = &this_cpu_ptr(&kvm_host_data)->host_ctxt;
-	host_ctxt->__hyp_running_vcpu = vcpu;
+	host_ctxt = host_data_ptr(host_ctxt);
 	guest_ctxt = &vcpu->arch.ctxt;
 
 	sysreg_save_host_state_vhe(host_ctxt);
@@ -258,7 +261,7 @@ static int __kvm_vcpu_run_vhe(struct kvm_vcpu *vcpu)
 
 	sysreg_restore_host_state_vhe(host_ctxt);
 
-	if (vcpu->arch.fp_state == FP_STATE_GUEST_OWNED)
+	if (*host_data_ptr(fp_owner) == FP_STATE_GUEST_OWNED)
 		__fpsimd_save_fpexc32(vcpu);
 
 	__debug_switch_to_host(vcpu);
@@ -306,7 +309,7 @@ static void __hyp_call_panic(u64 spsr, u64 elr, u64 par)
 	struct kvm_cpu_context *host_ctxt;
 	struct kvm_vcpu *vcpu;
 
-	host_ctxt = &this_cpu_ptr(&kvm_host_data)->host_ctxt;
+	host_ctxt = host_data_ptr(host_ctxt);
 	vcpu = host_ctxt->__hyp_running_vcpu;
 
 	__deactivate_traps(vcpu);
diff --git a/arch/arm64/kvm/hyp/vhe/sysreg-sr.c b/arch/arm64/kvm/hyp/vhe/sysreg-sr.c
index a8b9ea496706..e12bd7d6d2dc 100644
--- a/arch/arm64/kvm/hyp/vhe/sysreg-sr.c
+++ b/arch/arm64/kvm/hyp/vhe/sysreg-sr.c
@@ -67,7 +67,7 @@ void __vcpu_load_switch_sysregs(struct kvm_vcpu *vcpu)
 	struct kvm_cpu_context *guest_ctxt = &vcpu->arch.ctxt;
 	struct kvm_cpu_context *host_ctxt;
 
-	host_ctxt = &this_cpu_ptr(&kvm_host_data)->host_ctxt;
+	host_ctxt = host_data_ptr(host_ctxt);
 	__sysreg_save_user_state(host_ctxt);
 
 	/*
@@ -110,7 +110,7 @@ void __vcpu_put_switch_sysregs(struct kvm_vcpu *vcpu)
 	struct kvm_cpu_context *guest_ctxt = &vcpu->arch.ctxt;
 	struct kvm_cpu_context *host_ctxt;
 
-	host_ctxt = &this_cpu_ptr(&kvm_host_data)->host_ctxt;
+	host_ctxt = host_data_ptr(host_ctxt);
 
 	__sysreg_save_el1_state(guest_ctxt);
 	__sysreg_save_user_state(guest_ctxt);