From: Fuad Tabba <tabba@google.com>
To: kvmarm@lists.linux.dev
Cc: maz@kernel.org, will@kernel.org, qperret@google.com,
tabba@google.com, seanjc@google.com, alexandru.elisei@arm.com,
catalin.marinas@arm.com, philmd@linaro.org, james.morse@arm.com,
suzuki.poulose@arm.com, oliver.upton@linux.dev,
mark.rutland@arm.com, broonie@kernel.org, joey.gouly@arm.com,
rananta@google.com, smostafa@google.com
Subject: [PATCH v3 10/31] KVM: arm64: Do not map the host fpsimd state to hyp in pKVM
Date: Fri, 19 Apr 2024 08:59:20 +0100 [thread overview]
Message-ID: <20240419075941.4085061-11-tabba@google.com> (raw)
In-Reply-To: <20240419075941.4085061-1-tabba@google.com>
pKVM maintains its own state at EL2 for tracking the host fpsimd
state. Therefore, no need to map and share the host's view with
it.
Signed-off-by: Fuad Tabba <tabba@google.com>
Reviewed-by: Mark Brown <broonie@kernel.org>
---
arch/arm64/include/asm/kvm_host.h | 3 ---
arch/arm64/kvm/fpsimd.c | 31 ++++---------------------------
arch/arm64/kvm/reset.c | 1 -
3 files changed, 4 insertions(+), 31 deletions(-)
diff --git a/arch/arm64/include/asm/kvm_host.h b/arch/arm64/include/asm/kvm_host.h
index 4609d1b9ddde..74dc5a60f171 100644
--- a/arch/arm64/include/asm/kvm_host.h
+++ b/arch/arm64/include/asm/kvm_host.h
@@ -663,8 +663,6 @@ struct kvm_vcpu_arch {
struct kvm_guest_debug_arch vcpu_debug_state;
struct kvm_guest_debug_arch external_debug_state;
- struct task_struct *parent_task;
-
/* VGIC state */
struct vgic_cpu vgic_cpu;
struct arch_timer_cpu timer_cpu;
@@ -1262,7 +1260,6 @@ void kvm_arch_vcpu_load_fp(struct kvm_vcpu *vcpu);
void kvm_arch_vcpu_ctxflush_fp(struct kvm_vcpu *vcpu);
void kvm_arch_vcpu_ctxsync_fp(struct kvm_vcpu *vcpu);
void kvm_arch_vcpu_put_fp(struct kvm_vcpu *vcpu);
-void kvm_vcpu_unshare_task_fp(struct kvm_vcpu *vcpu);
static inline bool kvm_pmu_counter_deferred(struct perf_event_attr *attr)
{
diff --git a/arch/arm64/kvm/fpsimd.c b/arch/arm64/kvm/fpsimd.c
index d5837d65e4a1..63a6f82934a6 100644
--- a/arch/arm64/kvm/fpsimd.c
+++ b/arch/arm64/kvm/fpsimd.c
@@ -14,19 +14,6 @@
#include <asm/kvm_mmu.h>
#include <asm/sysreg.h>
-void kvm_vcpu_unshare_task_fp(struct kvm_vcpu *vcpu)
-{
- struct task_struct *p = vcpu->arch.parent_task;
- struct user_fpsimd_state *fpsimd;
-
- if (!is_protected_kvm_enabled() || !p)
- return;
-
- fpsimd = &p->thread.uw.fpsimd_state;
- kvm_unshare_hyp(fpsimd, fpsimd + 1);
- put_task_struct(p);
-}
-
/*
* Called on entry to KVM_RUN unless this vcpu previously ran at least
* once and the most recent prior KVM_RUN for this vcpu was called from
@@ -38,28 +25,18 @@ void kvm_vcpu_unshare_task_fp(struct kvm_vcpu *vcpu)
*/
int kvm_arch_vcpu_run_map_fp(struct kvm_vcpu *vcpu)
{
- int ret;
-
struct user_fpsimd_state *fpsimd = ¤t->thread.uw.fpsimd_state;
+ int ret;
- kvm_vcpu_unshare_task_fp(vcpu);
+ /* pKVM has its own tracking of the host fpsimd state. */
+ if (is_protected_kvm_enabled())
+ return 0;
/* Make sure the host task fpsimd state is visible to hyp: */
ret = kvm_share_hyp(fpsimd, fpsimd + 1);
if (ret)
return ret;
- /*
- * 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
- * kernel and donated to someone else while already shared -- see
- * kvm_vcpu_unshare_task_fp() for the matching put_task_struct().
- */
- if (is_protected_kvm_enabled()) {
- get_task_struct(current);
- vcpu->arch.parent_task = current;
- }
-
return 0;
}
diff --git a/arch/arm64/kvm/reset.c b/arch/arm64/kvm/reset.c
index 68d1d05672bd..1b7b58cb121f 100644
--- a/arch/arm64/kvm/reset.c
+++ b/arch/arm64/kvm/reset.c
@@ -151,7 +151,6 @@ void kvm_arm_vcpu_destroy(struct kvm_vcpu *vcpu)
{
void *sve_state = vcpu->arch.sve_state;
- kvm_vcpu_unshare_task_fp(vcpu);
kvm_unshare_hyp(vcpu, vcpu + 1);
if (sve_state)
kvm_unshare_hyp(sve_state, sve_state + vcpu_sve_state_size(vcpu));
--
2.44.0.769.g3c40516874-goog
next prev parent reply other threads:[~2024-04-19 8:00 UTC|newest]
Thread overview: 44+ messages / expand[flat|nested] mbox.gz Atom feed top
2024-04-19 7:59 [PATCH v3 00/31] KVM: arm64: Preamble for pKVM Fuad Tabba
2024-04-19 7:59 ` [PATCH v3 01/31] KVM: arm64: Initialize the kvm host data's fpsimd_state pointer in pKVM Fuad Tabba
2024-04-19 7:59 ` [PATCH v3 02/31] KVM: arm64: Move guest_owns_fp_regs() to increase its scope Fuad Tabba
2024-04-19 7:59 ` [PATCH v3 03/31] KVM: arm64: Refactor checks for FP state ownership Fuad Tabba
2024-04-19 7:59 ` [PATCH v3 04/31] KVM: arm64: Do not re-initialize the KVM lock Fuad Tabba
2024-04-19 7:59 ` [PATCH v3 05/31] KVM: arm64: Issue CMOs when tearing down guest s2 pages Fuad Tabba
2024-04-19 7:59 ` [PATCH v3 06/31] KVM: arm64: Avoid BUG-ing from the host abort path Fuad Tabba
2024-04-19 7:59 ` [PATCH v3 07/31] KVM: arm64: Check for PTE validity when checking for executable/cacheable Fuad Tabba
2024-04-19 7:59 ` [PATCH v3 08/31] KVM: arm64: Avoid BBM when changing only s/w bits in Stage-2 PTE Fuad Tabba
2024-04-19 7:59 ` [PATCH v3 09/31] KVM: arm64: Support TLB invalidation in guest context Fuad Tabba
2024-04-19 20:54 ` Oliver Upton
2024-04-22 8:11 ` Fuad Tabba
2024-04-19 7:59 ` Fuad Tabba [this message]
2024-04-19 7:59 ` [PATCH v3 11/31] KVM: arm64: Remove locking from EL2 allocation fast-paths Fuad Tabba
2024-04-19 20:42 ` Oliver Upton
2024-04-22 8:09 ` Fuad Tabba
2024-04-19 7:59 ` [PATCH v3 12/31] KVM: arm64: Prevent kmemleak from accessing .hyp.data Fuad Tabba
2024-04-19 7:59 ` [PATCH v3 13/31] KVM: arm64: Fix comment for __pkvm_vcpu_init_traps() Fuad Tabba
2024-04-19 7:59 ` [PATCH v3 14/31] KVM: arm64: Change kvm_handle_mmio_return() return polarity Fuad Tabba
2024-04-19 7:59 ` [PATCH v3 15/31] KVM: arm64: Move setting the page as dirty out of the critical section Fuad Tabba
2024-04-19 7:59 ` [PATCH v3 16/31] KVM: arm64: Simplify vgic-v3 hypercalls Fuad Tabba
2024-04-19 7:59 ` [PATCH v3 17/31] KVM: arm64: Add is_pkvm_initialized() helper Fuad Tabba
2024-04-19 7:59 ` [PATCH v3 18/31] KVM: arm64: Introduce and use predicates that check for protected VMs Fuad Tabba
2024-04-19 7:59 ` [PATCH v3 19/31] KVM: arm64: Move pstate reset value definitions to kvm_arm.h Fuad Tabba
2024-04-19 7:59 ` [PATCH v3 20/31] KVM: arm64: Clarify rationale for ZCR_EL1 value restored on guest exit Fuad Tabba
2024-04-19 7:59 ` [PATCH v3 21/31] KVM: arm64: Refactor calculating SVE state size to use helpers Fuad Tabba
2024-04-19 7:59 ` [PATCH v3 22/31] KVM: arm64: Move some kvm_psci functions to a shared header Fuad Tabba
2024-04-19 7:59 ` [PATCH v3 23/31] KVM: arm64: Refactor reset_mpidr() to extract its computation Fuad Tabba
2024-04-19 7:59 ` [PATCH v3 24/31] KVM: arm64: Refactor kvm_vcpu_enable_ptrauth() for hyp use Fuad Tabba
2024-04-19 7:59 ` [PATCH v3 25/31] KVM: arm64: Introduce hyp_rwlock_t Fuad Tabba
2024-04-19 7:59 ` [PATCH v3 26/31] KVM: arm64: Add atomics-based checking refcount implementation at EL2 Fuad Tabba
2024-04-19 7:59 ` [PATCH v3 27/31] KVM: arm64: Use atomic refcount helpers for 'struct hyp_page::refcount' Fuad Tabba
2024-04-19 20:52 ` Oliver Upton
2024-04-22 8:10 ` Fuad Tabba
2024-04-22 13:08 ` Fuad Tabba
2024-04-22 20:46 ` Oliver Upton
2024-04-22 23:44 ` Will Deacon
2024-04-23 1:15 ` Oliver Upton
2024-04-19 7:59 ` [PATCH v3 28/31] KVM: arm64: Reformat/beautify PTP hypercall documentation Fuad Tabba
2024-04-19 7:59 ` [PATCH v3 29/31] KVM: arm64: Rename firmware pseudo-register documentation file Fuad Tabba
2024-04-19 7:59 ` [PATCH v3 30/31] KVM: arm64: Document the KVM/arm64-specific calls in hypercalls.rst Fuad Tabba
2024-04-19 7:59 ` [PATCH v3 31/31] KVM: arm64: Force injection of a data abort on NISV MMIO exit Fuad Tabba
2024-04-19 20:28 ` Oliver Upton
2024-04-22 8:07 ` Fuad Tabba
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