On 09/04/2014 09:13 PM, Aravinda Prasad wrote:
> Whenever there is a physical memory error due to bit
> flips, which cannot be corrected by hardware, the error
> is passed on to the kernel. If the memory address in
> error belongs to guest address space then guest kernel
> is responsible to take action. Hence the error is passed
> on to guest via KVM by invoking 0x200 NMI vector.
>
> However, guest OS, as per PAPR, expects an error log
> upon such error. This patch registers a new hcall
> which is issued from 0x200 interrupt vector and builds
> the error log, copies the error log to rtas space and
> passes the address of the error log to guest
>
> Enhancement to KVM to perform above functionality is
> already in upstream kernel.
>
> Signed-off-by: Aravinda Prasad <aravi...@linux.vnet.ibm.com>
> ---
> hw/ppc/spapr_hcall.c | 154
> ++++++++++++++++++++++++++++++++++++++++++++++++
> include/hw/ppc/spapr.h | 4 +
> 2 files changed, 157 insertions(+), 1 deletion(-)
>
> diff --git a/hw/ppc/spapr_hcall.c b/hw/ppc/spapr_hcall.c
> index 01650ba..c3aa448 100644
> --- a/hw/ppc/spapr_hcall.c
> +++ b/hw/ppc/spapr_hcall.c
> @@ -14,6 +14,88 @@ struct SPRSyncState {
> target_ulong mask;
> };
>
> +/* Offset from rtas-base where error log is placed */
> +#define RTAS_ERROR_OFFSET (TARGET_PAGE_SIZE)
> +
> +#define RTAS_ELOG_SEVERITY_SHIFT 0x5
> +#define RTAS_ELOG_DISPOSITION_SHIFT 0x3
> +#define RTAS_ELOG_INITIATOR_SHIFT 0x4
> +
> +/*
> + * Only required RTAS event severity, disposition, initiator
> + * target and type are copied from arch/powerpc/include/asm/rtas.h
> + */
> +
> +/* RTAS event severity */
> +#define RTAS_SEVERITY_ERROR_SYNC 0x3
> +
> +/* RTAS event disposition */
> +#define RTAS_DISP_NOT_RECOVERED 0x2
> +
> +/* RTAS event initiator */
> +#define RTAS_INITIATOR_MEMORY 0x4
> +
> +/* RTAS event target */
> +#define RTAS_TARGET_MEMORY 0x4
> +
> +/* RTAS event type */
> +#define RTAS_TYPE_ECC_UNCORR 0x09
> +
> +/*
> + * Currently KVM only passes on the uncorrected machine
> + * check memory error to guest. Other machine check errors
> + * such as SLB multi-hit and TLB multi-hit are recovered
> + * in KVM and are not passed on to guest.
> + *
> + * DSISR Bit for uncorrected machine check error. Based
> + * on arch/powerpc/include/asm/mce.h
> + */
> +#define PPC_BIT(bit) (0x8000000000000000ULL >> bit)
> +#define P7_DSISR_MC_UE (PPC_BIT(48)) /* P8 too */
> +
> +/* Adopted from kernel source arch/powerpc/include/asm/rtas.h */
> +struct rtas_error_log {
> + /* Byte 0 */
> + uint8_t byte0; /* Architectural version */
> +
> + /* Byte 1 */
> + uint8_t byte1;
> + /* XXXXXXXX
> + * XXX 3: Severity level of error
> + * XX 2: Degree of recovery
> + * X 1: Extended log present?
> + * XX 2: Reserved
> + */
> +
> + /* Byte 2 */
> + uint8_t byte2;
> + /* XXXXXXXX
> + * XXXX 4: Initiator of event
> + * XXXX 4: Target of failed operation
> + */
> + uint8_t byte3; /* General event or error*/
> +};
Any particular reason not to copy rtas_error_log as is?
--
Alexey Kardashevskiy
IBM OzLabs, LTC Team
e-mail: a...@au1.ibm.com
notes: Alexey Kardashevskiy/Australia/IBM
