[PATCH v9 6/7] arm64: kvm: Set Virtual SError Exception Syndrome for guest
From: james.morse@arm.com (James Morse)
Date: 2018-01-23 19:10:16
Also in:
kvmarm, linux-acpi, lkml
Hi Dongjiu Geng, On 06/01/18 16:02, Dongjiu Geng wrote:
RAS Extension add a VSESR_EL2 register which can provide the syndrome value reported to software on taking a virtual SError interrupt exception. This patch supports to specify this Syndrome. In the RAS Extensions we can not set all-zero syndrome value for SError, which means 'RAS error: Uncategorized' instead of 'no valid ISS'. So set it to IMPLEMENTATION DEFINED syndrome by default. We also need to support userspace to specify a valid syndrome value, Because in some case, the recovery is driven by userspace. This patch can support that userspace specify it. In the guest/host world switch, restore this value to VSESR_EL2 only when HCR_EL2.VSE is set. This value no need to be saved because it is stale vale when guest exit.
A version of this patch has been queued by Catalin. Now that the cpufeature bits are queued, I think this can be split up into two separate series for v4.16-rc1, one to tackle NOTIFY_SEI and the associated plumbing. The second for the KVM 'make SError pending' API.
Signed-off-by: Dongjiu Geng <redacted> [Set an impdef ESR for Virtual-SError] Signed-off-by: James Morse <james.morse@arm.com>
I didn't sign-off this patch. If you pick some bits from another version and want to credit someone else you can 'CC:' them or just mention it in the commit-message.
quoted hunk ↗ jump to hunk
diff --git a/arch/arm64/include/asm/sysreg.h b/arch/arm64/include/asm/sysreg.h index 47b967d..3b035cc 100644 --- a/arch/arm64/include/asm/sysreg.h +++ b/arch/arm64/include/asm/sysreg.h@@ -86,6 +86,9 @@ #define REG_PSTATE_PAN_IMM sys_reg(0, 0, 4, 0, 4) #define REG_PSTATE_UAO_IMM sys_reg(0, 0, 4, 0, 3) +/* virtual SError exception syndrome register */ +#define REG_VSESR_EL2 sys_reg(3, 4, 5, 2, 3)
Irrelevant-Nit: sys-regs usually have a 'SYS_' prefix, and are in instruction
encoding order lower down the file.
(These PSTATE PAN things are a bit odd as they were used to generate and
instruction before the fancy {read,write}_sysreg() helpers were added).
quoted hunk ↗ jump to hunk
#define SET_PSTATE_PAN(x) __emit_inst(0xd5000000 | REG_PSTATE_PAN_IMM | \ (!!x)<<8 | 0x1f) #define SET_PSTATE_UAO(x) __emit_inst(0xd5000000 | REG_PSTATE_UAO_IMM | \diff --git a/arch/arm64/kvm/guest.c b/arch/arm64/kvm/guest.c index 738ae90..ffad42b 100644 --- a/arch/arm64/kvm/guest.c +++ b/arch/arm64/kvm/guest.c@@ -279,7 +279,16 @@ int kvm_arch_vcpu_ioctl_set_sregs(struct kvm_vcpu *vcpu, int kvm_arm_set_sei_esr(struct kvm_vcpu *vcpu, u32 *syndrome)
Bits of this are spread between patches 5 and 6. If you put them in the other order this wouldn't happen. (but after a rebase most of this patch should disappear)
{
- return -EINVAL;
+ u64 reg = *syndrome;
+
+ /* inject virtual system Error or asynchronous abort */
+ kvm_inject_vabt(vcpu);So this writes an impdef ESR, because its the existing code-path in KVM.
+ if (reg) + /* set vsesr_el2[24:0] with value that user space specified */ + kvm_vcpu_set_vsesr(vcpu, reg & ESR_ELx_ISS_MASK);
And then you overwrite it. Which is a bit odd as there is a helper to do both in one go:
+ + return 0; }
int __attribute_const__ kvm_target_cpu(void)
quoted hunk ↗ jump to hunk
diff --git a/arch/arm64/kvm/inject_fault.c b/arch/arm64/kvm/inject_fault.c index 3556715..fb94b5e 100644 --- a/arch/arm64/kvm/inject_fault.c +++ b/arch/arm64/kvm/inject_fault.c@@ -246,14 +246,25 @@ void kvm_inject_undefined(struct kvm_vcpu *vcpu) inject_undef64(vcpu); } +static void pend_guest_serror(struct kvm_vcpu *vcpu, u64 esr) +{ + kvm_vcpu_set_vsesr(vcpu, esr); + vcpu_set_hcr(vcpu, vcpu_get_hcr(vcpu) | HCR_VSE); +}
How come you don't use this in kvm_arm_set_sei_esr()? Thanks, James