* [PATCH v2 0/2] KVM: arm64: Sanitise host vCPU fields copied in flush_hyp_vcpu()
@ 2026-06-04 15:12 Hyunwoo Kim
2026-06-04 15:12 ` [PATCH v2 1/2] KVM: arm64: Clear __hyp_running_vcpu when flushing the pKVM hyp vCPU Hyunwoo Kim
` (2 more replies)
0 siblings, 3 replies; 7+ messages in thread
From: Hyunwoo Kim @ 2026-06-04 15:12 UTC (permalink / raw)
To: tabba, maz, oupton, joey.gouly, seiden, suzuki.poulose, yuzenghui,
catalin.marinas, will
Cc: linux-arm-kernel, kvmarm, imv4bel
flush_hyp_vcpu() copies the host vCPU context and vGIC state into the
hyp's private vCPU on every run. This series sanitises two fields that
it currently copies verbatim (host -> EL2): __hyp_running_vcpu is
cleared in the guest context, and used_lrs is bounded by the number of
implemented list registers.
v1 -> v2: split into two patches, one per field, per review.
Hyunwoo Kim (2):
KVM: arm64: Clear __hyp_running_vcpu when flushing the pKVM hyp vCPU
KVM: arm64: Bound used_lrs when flushing the pKVM hyp vCPU
arch/arm64/kvm/hyp/nvhe/hyp-main.c | 11 +++++++++++
1 file changed, 11 insertions(+)
--
2.43.0
^ permalink raw reply [flat|nested] 7+ messages in thread* [PATCH v2 1/2] KVM: arm64: Clear __hyp_running_vcpu when flushing the pKVM hyp vCPU 2026-06-04 15:12 [PATCH v2 0/2] KVM: arm64: Sanitise host vCPU fields copied in flush_hyp_vcpu() Hyunwoo Kim @ 2026-06-04 15:12 ` Hyunwoo Kim 2026-06-04 15:12 ` [PATCH v2 2/2] KVM: arm64: Bound used_lrs " Hyunwoo Kim 2026-06-04 15:29 ` [PATCH v2 0/2] KVM: arm64: Sanitise host vCPU fields copied in flush_hyp_vcpu() Fuad Tabba 2 siblings, 0 replies; 7+ messages in thread From: Hyunwoo Kim @ 2026-06-04 15:12 UTC (permalink / raw) To: tabba, maz, oupton, joey.gouly, seiden, suzuki.poulose, yuzenghui, catalin.marinas, will Cc: linux-arm-kernel, kvmarm, imv4bel flush_hyp_vcpu() copies the host vCPU context into the hyp's private vCPU on every run. ctxt_to_vcpu() expects a guest context to have a NULL __hyp_running_vcpu, which is only ever set on the host context, so that it resolves the vCPU via container_of(). While this is generally the case, flush_hyp_vcpu() copies the context verbatim and does not enforce this, so a value provided by the host is dereferenced at EL2 (host -> EL2). Fix by clearing __hyp_running_vcpu after the copy. Fixes: be66e67f1750 ("KVM: arm64: Use the pKVM hyp vCPU structure in handle___kvm_vcpu_run()") Signed-off-by: Hyunwoo Kim <imv4bel@gmail.com> --- arch/arm64/kvm/hyp/nvhe/hyp-main.c | 3 +++ 1 file changed, 3 insertions(+) diff --git a/arch/arm64/kvm/hyp/nvhe/hyp-main.c b/arch/arm64/kvm/hyp/nvhe/hyp-main.c index 06db299c37a89..02c5d6e5abcbf 100644 --- a/arch/arm64/kvm/hyp/nvhe/hyp-main.c +++ b/arch/arm64/kvm/hyp/nvhe/hyp-main.c @@ -128,6 +128,9 @@ static void flush_hyp_vcpu(struct pkvm_hyp_vcpu *hyp_vcpu) hyp_vcpu->vcpu.arch.ctxt = host_vcpu->arch.ctxt; + /* __hyp_running_vcpu must be NULL in a guest context. */ + hyp_vcpu->vcpu.arch.ctxt.__hyp_running_vcpu = NULL; + hyp_vcpu->vcpu.arch.mdcr_el2 = host_vcpu->arch.mdcr_el2; hyp_vcpu->vcpu.arch.hcr_el2 &= ~(HCR_TWI | HCR_TWE); hyp_vcpu->vcpu.arch.hcr_el2 |= READ_ONCE(host_vcpu->arch.hcr_el2) & -- 2.43.0 ^ permalink raw reply related [flat|nested] 7+ messages in thread
* [PATCH v2 2/2] KVM: arm64: Bound used_lrs when flushing the pKVM hyp vCPU 2026-06-04 15:12 [PATCH v2 0/2] KVM: arm64: Sanitise host vCPU fields copied in flush_hyp_vcpu() Hyunwoo Kim 2026-06-04 15:12 ` [PATCH v2 1/2] KVM: arm64: Clear __hyp_running_vcpu when flushing the pKVM hyp vCPU Hyunwoo Kim @ 2026-06-04 15:12 ` Hyunwoo Kim 2026-06-05 8:58 ` Marc Zyngier 2026-06-04 15:29 ` [PATCH v2 0/2] KVM: arm64: Sanitise host vCPU fields copied in flush_hyp_vcpu() Fuad Tabba 2 siblings, 1 reply; 7+ messages in thread From: Hyunwoo Kim @ 2026-06-04 15:12 UTC (permalink / raw) To: tabba, maz, oupton, joey.gouly, seiden, suzuki.poulose, yuzenghui, catalin.marinas, will Cc: linux-arm-kernel, kvmarm, imv4bel flush_hyp_vcpu() copies the host vGIC state into the hyp's private vCPU on every run. The vGIC list register save and restore use used_lrs as their loop bound and expect it to stay within the number of implemented list registers. While this is generally the case, flush_hyp_vcpu() copies vgic_v3 verbatim and does not enforce this, so a value provided by the host is used at EL2 to index vgic_lr[] and access ICH_LR<n>_EL2 (host -> EL2). Fix by clamping used_lrs to the number of implemented list registers after the copy, as the trusted path already does in vgic_flush_lr_state(). Fixes: be66e67f1750 ("KVM: arm64: Use the pKVM hyp vCPU structure in handle___kvm_vcpu_run()") Signed-off-by: Hyunwoo Kim <imv4bel@gmail.com> --- arch/arm64/kvm/hyp/nvhe/hyp-main.c | 8 ++++++++ 1 file changed, 8 insertions(+) diff --git a/arch/arm64/kvm/hyp/nvhe/hyp-main.c b/arch/arm64/kvm/hyp/nvhe/hyp-main.c index 02c5d6e5abcbf..cd807fdb11ba8 100644 --- a/arch/arm64/kvm/hyp/nvhe/hyp-main.c +++ b/arch/arm64/kvm/hyp/nvhe/hyp-main.c @@ -7,6 +7,7 @@ #include <hyp/adjust_pc.h> #include <hyp/switch.h> +#include <asm/arch_gicv3.h> #include <asm/pgtable-types.h> #include <asm/kvm_asm.h> #include <asm/kvm_emulate.h> @@ -142,6 +143,13 @@ static void flush_hyp_vcpu(struct pkvm_hyp_vcpu *hyp_vcpu) hyp_vcpu->vcpu.arch.vgic_cpu.vgic_v3 = host_vcpu->arch.vgic_cpu.vgic_v3; + /* Bound used_lrs by the number of implemented list registers. */ + if (static_branch_unlikely(&kvm_vgic_global_state.gicv3_cpuif)) + hyp_vcpu->vcpu.arch.vgic_cpu.vgic_v3.used_lrs = + min_t(unsigned int, + hyp_vcpu->vcpu.arch.vgic_cpu.vgic_v3.used_lrs, + (read_gicreg(ICH_VTR_EL2) & 0xf) + 1); + hyp_vcpu->vcpu.arch.pid = host_vcpu->arch.pid; } -- 2.43.0 ^ permalink raw reply related [flat|nested] 7+ messages in thread
* Re: [PATCH v2 2/2] KVM: arm64: Bound used_lrs when flushing the pKVM hyp vCPU 2026-06-04 15:12 ` [PATCH v2 2/2] KVM: arm64: Bound used_lrs " Hyunwoo Kim @ 2026-06-05 8:58 ` Marc Zyngier 2026-06-06 8:52 ` Hyunwoo Kim 0 siblings, 1 reply; 7+ messages in thread From: Marc Zyngier @ 2026-06-05 8:58 UTC (permalink / raw) To: Hyunwoo Kim Cc: tabba, oupton, joey.gouly, seiden, suzuki.poulose, yuzenghui, catalin.marinas, will, linux-arm-kernel, kvmarm On Thu, 04 Jun 2026 16:12:03 +0100, Hyunwoo Kim <imv4bel@gmail.com> wrote: > > flush_hyp_vcpu() copies the host vGIC state into the hyp's private vCPU > on every run. The vGIC list register save and restore use used_lrs as > their loop bound and expect it to stay within the number of implemented > list registers. While this is generally the case, flush_hyp_vcpu() > copies vgic_v3 verbatim and does not enforce this, so a value provided > by the host is used at EL2 to index vgic_lr[] and access ICH_LR<n>_EL2 > (host -> EL2). > > Fix by clamping used_lrs to the number of implemented list registers > after the copy, as the trusted path already does in > vgic_flush_lr_state(). > > Fixes: be66e67f1750 ("KVM: arm64: Use the pKVM hyp vCPU structure in handle___kvm_vcpu_run()") > Signed-off-by: Hyunwoo Kim <imv4bel@gmail.com> > --- > arch/arm64/kvm/hyp/nvhe/hyp-main.c | 8 ++++++++ > 1 file changed, 8 insertions(+) > > diff --git a/arch/arm64/kvm/hyp/nvhe/hyp-main.c b/arch/arm64/kvm/hyp/nvhe/hyp-main.c > index 02c5d6e5abcbf..cd807fdb11ba8 100644 > --- a/arch/arm64/kvm/hyp/nvhe/hyp-main.c > +++ b/arch/arm64/kvm/hyp/nvhe/hyp-main.c > @@ -7,6 +7,7 @@ > #include <hyp/adjust_pc.h> > #include <hyp/switch.h> > > +#include <asm/arch_gicv3.h> > #include <asm/pgtable-types.h> > #include <asm/kvm_asm.h> > #include <asm/kvm_emulate.h> > @@ -142,6 +143,13 @@ static void flush_hyp_vcpu(struct pkvm_hyp_vcpu *hyp_vcpu) > > hyp_vcpu->vcpu.arch.vgic_cpu.vgic_v3 = host_vcpu->arch.vgic_cpu.vgic_v3; > > + /* Bound used_lrs by the number of implemented list registers. */ > + if (static_branch_unlikely(&kvm_vgic_global_state.gicv3_cpuif)) There is no pKVM support without a GICv3 CPU interface, and absolutely everything already assumes it. Why do we need this extra check? > + hyp_vcpu->vcpu.arch.vgic_cpu.vgic_v3.used_lrs = > + min_t(unsigned int, > + hyp_vcpu->vcpu.arch.vgic_cpu.vgic_v3.used_lrs, > + (read_gicreg(ICH_VTR_EL2) & 0xf) + 1); > + Reading ICH_VTR_EL2 on each entry is going to cause some really heavy trapping under NV, and we should avoid this. kvm_vgic_global_state.nr_lr contains this information, and it should only be a matter of replicating it (or compute it once) at init time. Thanks, M. -- Without deviation from the norm, progress is not possible. ^ permalink raw reply [flat|nested] 7+ messages in thread
* Re: [PATCH v2 2/2] KVM: arm64: Bound used_lrs when flushing the pKVM hyp vCPU 2026-06-05 8:58 ` Marc Zyngier @ 2026-06-06 8:52 ` Hyunwoo Kim 2026-06-06 10:52 ` Marc Zyngier 0 siblings, 1 reply; 7+ messages in thread From: Hyunwoo Kim @ 2026-06-06 8:52 UTC (permalink / raw) To: Marc Zyngier Cc: tabba, oupton, joey.gouly, seiden, suzuki.poulose, yuzenghui, catalin.marinas, will, linux-arm-kernel, kvmarm, imv4bel On Fri, Jun 05, 2026 at 09:58:09AM +0100, Marc Zyngier wrote: > On Thu, 04 Jun 2026 16:12:03 +0100, > Hyunwoo Kim <imv4bel@gmail.com> wrote: > > > > flush_hyp_vcpu() copies the host vGIC state into the hyp's private vCPU > > on every run. The vGIC list register save and restore use used_lrs as > > their loop bound and expect it to stay within the number of implemented > > list registers. While this is generally the case, flush_hyp_vcpu() > > copies vgic_v3 verbatim and does not enforce this, so a value provided > > by the host is used at EL2 to index vgic_lr[] and access ICH_LR<n>_EL2 > > (host -> EL2). > > > > Fix by clamping used_lrs to the number of implemented list registers > > after the copy, as the trusted path already does in > > vgic_flush_lr_state(). > > > > Fixes: be66e67f1750 ("KVM: arm64: Use the pKVM hyp vCPU structure in handle___kvm_vcpu_run()") > > Signed-off-by: Hyunwoo Kim <imv4bel@gmail.com> > > --- > > arch/arm64/kvm/hyp/nvhe/hyp-main.c | 8 ++++++++ > > 1 file changed, 8 insertions(+) > > > > diff --git a/arch/arm64/kvm/hyp/nvhe/hyp-main.c b/arch/arm64/kvm/hyp/nvhe/hyp-main.c > > index 02c5d6e5abcbf..cd807fdb11ba8 100644 > > --- a/arch/arm64/kvm/hyp/nvhe/hyp-main.c > > +++ b/arch/arm64/kvm/hyp/nvhe/hyp-main.c > > @@ -7,6 +7,7 @@ > > #include <hyp/adjust_pc.h> > > #include <hyp/switch.h> > > > > +#include <asm/arch_gicv3.h> > > #include <asm/pgtable-types.h> > > #include <asm/kvm_asm.h> > > #include <asm/kvm_emulate.h> > > @@ -142,6 +143,13 @@ static void flush_hyp_vcpu(struct pkvm_hyp_vcpu *hyp_vcpu) > > > > hyp_vcpu->vcpu.arch.vgic_cpu.vgic_v3 = host_vcpu->arch.vgic_cpu.vgic_v3; > > > > + /* Bound used_lrs by the number of implemented list registers. */ > > + if (static_branch_unlikely(&kvm_vgic_global_state.gicv3_cpuif)) > > There is no pKVM support without a GICv3 CPU interface, and absolutely > everything already assumes it. Why do we need this extra check? > > > + hyp_vcpu->vcpu.arch.vgic_cpu.vgic_v3.used_lrs = > > + min_t(unsigned int, > > + hyp_vcpu->vcpu.arch.vgic_cpu.vgic_v3.used_lrs, > > + (read_gicreg(ICH_VTR_EL2) & 0xf) + 1); > > + > > Reading ICH_VTR_EL2 on each entry is going to cause some really heavy > trapping under NV, and we should avoid this. > > kvm_vgic_global_state.nr_lr contains this information, and it should > only be a matter of replicating it (or compute it once) at init time. Does this approach look reasonable to you? --- diff --git a/arch/arm64/include/asm/kvm_hyp.h b/arch/arm64/include/asm/kvm_hyp.h index 8d06b62e7188..25199769a1d6 100644 --- a/arch/arm64/include/asm/kvm_hyp.h +++ b/arch/arm64/include/asm/kvm_hyp.h @@ -157,5 +157,6 @@ extern unsigned long kvm_nvhe_sym(__icache_flags); extern unsigned int kvm_nvhe_sym(kvm_arm_vmid_bits); extern unsigned int kvm_nvhe_sym(kvm_host_sve_max_vl); extern unsigned long kvm_nvhe_sym(hyp_nr_cpus); +extern unsigned int kvm_nvhe_sym(hyp_vgic_nr_lr); #endif /* __ARM64_KVM_HYP_H__ */ diff --git a/arch/arm64/kvm/arm.c b/arch/arm64/kvm/arm.c index 9453321ef8c6..891fe2c7b854 100644 --- a/arch/arm64/kvm/arm.c +++ b/arch/arm64/kvm/arm.c @@ -2426,6 +2426,7 @@ static int __init init_subsystems(void) switch (err) { case 0: vgic_present = true; + kvm_nvhe_sym(hyp_vgic_nr_lr) = kvm_vgic_global_state.nr_lr; break; case -ENODEV: case -ENXIO: diff --git a/arch/arm64/kvm/hyp/nvhe/hyp-main.c b/arch/arm64/kvm/hyp/nvhe/hyp-main.c index 06db299c37a8..8bb9362bc284 100644 --- a/arch/arm64/kvm/hyp/nvhe/hyp-main.c +++ b/arch/arm64/kvm/hyp/nvhe/hyp-main.c @@ -128,6 +128,9 @@ static void flush_hyp_vcpu(struct pkvm_hyp_vcpu *hyp_vcpu) hyp_vcpu->vcpu.arch.ctxt = host_vcpu->arch.ctxt; + /* A guest context must keep a NULL __hyp_running_vcpu. */ + hyp_vcpu->vcpu.arch.ctxt.__hyp_running_vcpu = NULL; + hyp_vcpu->vcpu.arch.mdcr_el2 = host_vcpu->arch.mdcr_el2; hyp_vcpu->vcpu.arch.hcr_el2 &= ~(HCR_TWI | HCR_TWE); hyp_vcpu->vcpu.arch.hcr_el2 |= READ_ONCE(host_vcpu->arch.hcr_el2) & @@ -139,6 +142,12 @@ static void flush_hyp_vcpu(struct pkvm_hyp_vcpu *hyp_vcpu) hyp_vcpu->vcpu.arch.vgic_cpu.vgic_v3 = host_vcpu->arch.vgic_cpu.vgic_v3; + /* Bound used_lrs by the number of implemented list registers. */ + hyp_vcpu->vcpu.arch.vgic_cpu.vgic_v3.used_lrs = + min_t(unsigned int, + hyp_vcpu->vcpu.arch.vgic_cpu.vgic_v3.used_lrs, + hyp_vgic_nr_lr); + hyp_vcpu->vcpu.arch.pid = host_vcpu->arch.pid; } diff --git a/arch/arm64/kvm/hyp/nvhe/setup.c b/arch/arm64/kvm/hyp/nvhe/setup.c index d461981616d9..ebc6b4afc336 100644 --- a/arch/arm64/kvm/hyp/nvhe/setup.c +++ b/arch/arm64/kvm/hyp/nvhe/setup.c @@ -20,6 +20,7 @@ #include <nvhe/trap_handler.h> unsigned long hyp_nr_cpus; +unsigned int hyp_vgic_nr_lr; #define hyp_percpu_size ((unsigned long)__per_cpu_end - \ (unsigned long)__per_cpu_start) > > Thanks, > > M. > > -- > Without deviation from the norm, progress is not possible. Best regards, Hyunwoo Kim ^ permalink raw reply related [flat|nested] 7+ messages in thread
* Re: [PATCH v2 2/2] KVM: arm64: Bound used_lrs when flushing the pKVM hyp vCPU 2026-06-06 8:52 ` Hyunwoo Kim @ 2026-06-06 10:52 ` Marc Zyngier 0 siblings, 0 replies; 7+ messages in thread From: Marc Zyngier @ 2026-06-06 10:52 UTC (permalink / raw) To: Hyunwoo Kim Cc: tabba, oupton, joey.gouly, seiden, suzuki.poulose, yuzenghui, catalin.marinas, will, linux-arm-kernel, kvmarm On Sat, 06 Jun 2026 09:52:08 +0100, Hyunwoo Kim <imv4bel@gmail.com> wrote: > > On Fri, Jun 05, 2026 at 09:58:09AM +0100, Marc Zyngier wrote: > > On Thu, 04 Jun 2026 16:12:03 +0100, > > Hyunwoo Kim <imv4bel@gmail.com> wrote: > > > > > > flush_hyp_vcpu() copies the host vGIC state into the hyp's private vCPU > > > on every run. The vGIC list register save and restore use used_lrs as > > > their loop bound and expect it to stay within the number of implemented > > > list registers. While this is generally the case, flush_hyp_vcpu() > > > copies vgic_v3 verbatim and does not enforce this, so a value provided > > > by the host is used at EL2 to index vgic_lr[] and access ICH_LR<n>_EL2 > > > (host -> EL2). > > > > > > Fix by clamping used_lrs to the number of implemented list registers > > > after the copy, as the trusted path already does in > > > vgic_flush_lr_state(). > > > > > > Fixes: be66e67f1750 ("KVM: arm64: Use the pKVM hyp vCPU structure in handle___kvm_vcpu_run()") > > > Signed-off-by: Hyunwoo Kim <imv4bel@gmail.com> > > > --- > > > arch/arm64/kvm/hyp/nvhe/hyp-main.c | 8 ++++++++ > > > 1 file changed, 8 insertions(+) > > > > > > diff --git a/arch/arm64/kvm/hyp/nvhe/hyp-main.c b/arch/arm64/kvm/hyp/nvhe/hyp-main.c > > > index 02c5d6e5abcbf..cd807fdb11ba8 100644 > > > --- a/arch/arm64/kvm/hyp/nvhe/hyp-main.c > > > +++ b/arch/arm64/kvm/hyp/nvhe/hyp-main.c > > > @@ -7,6 +7,7 @@ > > > #include <hyp/adjust_pc.h> > > > #include <hyp/switch.h> > > > > > > +#include <asm/arch_gicv3.h> > > > #include <asm/pgtable-types.h> > > > #include <asm/kvm_asm.h> > > > #include <asm/kvm_emulate.h> > > > @@ -142,6 +143,13 @@ static void flush_hyp_vcpu(struct pkvm_hyp_vcpu *hyp_vcpu) > > > > > > hyp_vcpu->vcpu.arch.vgic_cpu.vgic_v3 = host_vcpu->arch.vgic_cpu.vgic_v3; > > > > > > + /* Bound used_lrs by the number of implemented list registers. */ > > > + if (static_branch_unlikely(&kvm_vgic_global_state.gicv3_cpuif)) > > > > There is no pKVM support without a GICv3 CPU interface, and absolutely > > everything already assumes it. Why do we need this extra check? > > > > > + hyp_vcpu->vcpu.arch.vgic_cpu.vgic_v3.used_lrs = > > > + min_t(unsigned int, > > > + hyp_vcpu->vcpu.arch.vgic_cpu.vgic_v3.used_lrs, > > > + (read_gicreg(ICH_VTR_EL2) & 0xf) + 1); > > > + > > > > Reading ICH_VTR_EL2 on each entry is going to cause some really heavy > > trapping under NV, and we should avoid this. > > > > kvm_vgic_global_state.nr_lr contains this information, and it should > > only be a matter of replicating it (or compute it once) at init time. > > Does this approach look reasonable to you? > > --- > > diff --git a/arch/arm64/include/asm/kvm_hyp.h b/arch/arm64/include/asm/kvm_hyp.h > index 8d06b62e7188..25199769a1d6 100644 > --- a/arch/arm64/include/asm/kvm_hyp.h > +++ b/arch/arm64/include/asm/kvm_hyp.h > @@ -157,5 +157,6 @@ extern unsigned long kvm_nvhe_sym(__icache_flags); > extern unsigned int kvm_nvhe_sym(kvm_arm_vmid_bits); > extern unsigned int kvm_nvhe_sym(kvm_host_sve_max_vl); > extern unsigned long kvm_nvhe_sym(hyp_nr_cpus); > +extern unsigned int kvm_nvhe_sym(hyp_vgic_nr_lr); > > #endif /* __ARM64_KVM_HYP_H__ */ > diff --git a/arch/arm64/kvm/arm.c b/arch/arm64/kvm/arm.c > index 9453321ef8c6..891fe2c7b854 100644 > --- a/arch/arm64/kvm/arm.c > +++ b/arch/arm64/kvm/arm.c > @@ -2426,6 +2426,7 @@ static int __init init_subsystems(void) > switch (err) { > case 0: > vgic_present = true; > + kvm_nvhe_sym(hyp_vgic_nr_lr) = kvm_vgic_global_state.nr_lr; You probably want to guard this on kvm_vgic_global_state.gicv3_cpuif to be sure this stays to 0 when running with a GICv2 implementation. And maybe rename it to hyp_gicv3_nr_lr to avoid any confusion. > break; > case -ENODEV: > case -ENXIO: > diff --git a/arch/arm64/kvm/hyp/nvhe/hyp-main.c b/arch/arm64/kvm/hyp/nvhe/hyp-main.c > index 06db299c37a8..8bb9362bc284 100644 > --- a/arch/arm64/kvm/hyp/nvhe/hyp-main.c > +++ b/arch/arm64/kvm/hyp/nvhe/hyp-main.c > @@ -128,6 +128,9 @@ static void flush_hyp_vcpu(struct pkvm_hyp_vcpu *hyp_vcpu) > > hyp_vcpu->vcpu.arch.ctxt = host_vcpu->arch.ctxt; > > + /* A guest context must keep a NULL __hyp_running_vcpu. */ > + hyp_vcpu->vcpu.arch.ctxt.__hyp_running_vcpu = NULL; > + > hyp_vcpu->vcpu.arch.mdcr_el2 = host_vcpu->arch.mdcr_el2; > hyp_vcpu->vcpu.arch.hcr_el2 &= ~(HCR_TWI | HCR_TWE); > hyp_vcpu->vcpu.arch.hcr_el2 |= READ_ONCE(host_vcpu->arch.hcr_el2) & > @@ -139,6 +142,12 @@ static void flush_hyp_vcpu(struct pkvm_hyp_vcpu *hyp_vcpu) > > hyp_vcpu->vcpu.arch.vgic_cpu.vgic_v3 = host_vcpu->arch.vgic_cpu.vgic_v3; > > + /* Bound used_lrs by the number of implemented list registers. */ > + hyp_vcpu->vcpu.arch.vgic_cpu.vgic_v3.used_lrs = > + min_t(unsigned int, > + hyp_vcpu->vcpu.arch.vgic_cpu.vgic_v3.used_lrs, > + hyp_vgic_nr_lr); > + > hyp_vcpu->vcpu.arch.pid = host_vcpu->arch.pid; > } > > diff --git a/arch/arm64/kvm/hyp/nvhe/setup.c b/arch/arm64/kvm/hyp/nvhe/setup.c > index d461981616d9..ebc6b4afc336 100644 > --- a/arch/arm64/kvm/hyp/nvhe/setup.c > +++ b/arch/arm64/kvm/hyp/nvhe/setup.c > @@ -20,6 +20,7 @@ > #include <nvhe/trap_handler.h> > > unsigned long hyp_nr_cpus; > +unsigned int hyp_vgic_nr_lr; You could probably move this close to the place where it is used instead of an unrelated file. Other than that, and with the vcpu-related hunk in its own patch, this looks reasonable. Thanks, M. -- Jazz isn't dead. It just smells funny. ^ permalink raw reply [flat|nested] 7+ messages in thread
* Re: [PATCH v2 0/2] KVM: arm64: Sanitise host vCPU fields copied in flush_hyp_vcpu() 2026-06-04 15:12 [PATCH v2 0/2] KVM: arm64: Sanitise host vCPU fields copied in flush_hyp_vcpu() Hyunwoo Kim 2026-06-04 15:12 ` [PATCH v2 1/2] KVM: arm64: Clear __hyp_running_vcpu when flushing the pKVM hyp vCPU Hyunwoo Kim 2026-06-04 15:12 ` [PATCH v2 2/2] KVM: arm64: Bound used_lrs " Hyunwoo Kim @ 2026-06-04 15:29 ` Fuad Tabba 2 siblings, 0 replies; 7+ messages in thread From: Fuad Tabba @ 2026-06-04 15:29 UTC (permalink / raw) To: Hyunwoo Kim Cc: maz, oupton, joey.gouly, seiden, suzuki.poulose, yuzenghui, catalin.marinas, will, linux-arm-kernel, kvmarm On Thu, 4 Jun 2026 at 16:12, Hyunwoo Kim <imv4bel@gmail.com> wrote: > > flush_hyp_vcpu() copies the host vCPU context and vGIC state into the > hyp's private vCPU on every run. This series sanitises two fields that > it currently copies verbatim (host -> EL2): __hyp_running_vcpu is > cleared in the guest context, and used_lrs is bounded by the number of > implemented list registers. > > v1 -> v2: split into two patches, one per field, per review. For the series: Reviewed-by: Fuad Tabba <tabba@google.com> Tested-by: Fuad Tabba <tabba@google.com> Cheers, /fuad > > Hyunwoo Kim (2): > KVM: arm64: Clear __hyp_running_vcpu when flushing the pKVM hyp vCPU > KVM: arm64: Bound used_lrs when flushing the pKVM hyp vCPU > > arch/arm64/kvm/hyp/nvhe/hyp-main.c | 11 +++++++++++ > 1 file changed, 11 insertions(+) > > -- > 2.43.0 > ^ permalink raw reply [flat|nested] 7+ messages in thread
end of thread, other threads:[~2026-06-06 10:49 UTC | newest] Thread overview: 7+ messages (download: mbox.gz follow: Atom feed -- links below jump to the message on this page -- 2026-06-04 15:12 [PATCH v2 0/2] KVM: arm64: Sanitise host vCPU fields copied in flush_hyp_vcpu() Hyunwoo Kim 2026-06-04 15:12 ` [PATCH v2 1/2] KVM: arm64: Clear __hyp_running_vcpu when flushing the pKVM hyp vCPU Hyunwoo Kim 2026-06-04 15:12 ` [PATCH v2 2/2] KVM: arm64: Bound used_lrs " Hyunwoo Kim 2026-06-05 8:58 ` Marc Zyngier 2026-06-06 8:52 ` Hyunwoo Kim 2026-06-06 10:52 ` Marc Zyngier 2026-06-04 15:29 ` [PATCH v2 0/2] KVM: arm64: Sanitise host vCPU fields copied in flush_hyp_vcpu() Fuad Tabba
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