path: root/arch/arm/kvm
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authorMarc Zyngier <marc.zyngier@arm.com>2018-01-21 16:42:56 +0000
committerMarc Zyngier <marc.zyngier@arm.com>2018-04-20 16:32:23 +0100
commit85bd0ba1ff9875798fad94218b627ea9f768f3c3 (patch)
tree7a1d8741a980a8d8d0a235c1784b2121634a9265 /arch/arm/kvm
parentbf9a41377d14f565764022470e14aae72559589a (diff)
arm/arm64: KVM: Add PSCI version selection API
Although we've implemented PSCI 0.1, 0.2 and 1.0, we expose either 0.1 or 1.0 to a guest, defaulting to the latest version of the PSCI implementation that is compatible with the requested version. This is no different from doing a firmware upgrade on KVM. But in order to give a chance to hypothetical badly implemented guests that would have a fit by discovering something other than PSCI 0.2, let's provide a new API that allows userspace to pick one particular version of the API. This is implemented as a new class of "firmware" registers, where we expose the PSCI version. This allows the PSCI version to be save/restored as part of a guest migration, and also set to any supported version if the guest requires it. Cc: stable@vger.kernel.org #4.16 Reviewed-by: Christoffer Dall <cdall@kernel.org> Signed-off-by: Marc Zyngier <marc.zyngier@arm.com>
Diffstat (limited to 'arch/arm/kvm')
1 files changed, 13 insertions, 0 deletions
diff --git a/arch/arm/kvm/guest.c b/arch/arm/kvm/guest.c
index 1e0784ebbfd6..a18f33edc471 100644
--- a/arch/arm/kvm/guest.c
+++ b/arch/arm/kvm/guest.c
@@ -22,6 +22,7 @@
#include <linux/module.h>
#include <linux/vmalloc.h>
#include <linux/fs.h>
+#include <kvm/arm_psci.h>
#include <asm/cputype.h>
#include <linux/uaccess.h>
#include <asm/kvm.h>
@@ -176,6 +177,7 @@ static unsigned long num_core_regs(void)
unsigned long kvm_arm_num_regs(struct kvm_vcpu *vcpu)
return num_core_regs() + kvm_arm_num_coproc_regs(vcpu)
+ + kvm_arm_get_fw_num_regs(vcpu)
@@ -196,6 +198,11 @@ int kvm_arm_copy_reg_indices(struct kvm_vcpu *vcpu, u64 __user *uindices)
+ ret = kvm_arm_copy_fw_reg_indices(vcpu, uindices);
+ if (ret)
+ return ret;
+ uindices += kvm_arm_get_fw_num_regs(vcpu);
ret = copy_timer_indices(vcpu, uindices);
if (ret)
return ret;
@@ -214,6 +221,9 @@ int kvm_arm_get_reg(struct kvm_vcpu *vcpu, const struct kvm_one_reg *reg)
return get_core_reg(vcpu, reg);
+ if ((reg->id & KVM_REG_ARM_COPROC_MASK) == KVM_REG_ARM_FW)
+ return kvm_arm_get_fw_reg(vcpu, reg);
if (is_timer_reg(reg->id))
return get_timer_reg(vcpu, reg);
@@ -230,6 +240,9 @@ int kvm_arm_set_reg(struct kvm_vcpu *vcpu, const struct kvm_one_reg *reg)
return set_core_reg(vcpu, reg);
+ if ((reg->id & KVM_REG_ARM_COPROC_MASK) == KVM_REG_ARM_FW)
+ return kvm_arm_set_fw_reg(vcpu, reg);
if (is_timer_reg(reg->id))
return set_timer_reg(vcpu, reg);

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