diff options
| author | Amit Machhiwal <amachhiw@linux.ibm.com> | 2024-10-18 22:08:49 +0530 |
|---|---|---|
| committer | Nicholas Piggin <npiggin@gmail.com> | 2024-11-04 09:13:01 +1000 |
| commit | 1d7e6318afcf060f4cd6ae3681d29a6cddf294ff (patch) | |
| tree | 54f8a8677c187418f7e9461bc523f41b83177a0c | |
| parent | 57ff60c1c2fbf21dbe81873dfb440edde15354b4 (diff) | |
spapr: nested: Add support for DPDES SPR in GSB for TCG L0
The DPDES support for doorbell emulation and handling for KVM on PAPR
guests was added in Linux via [1]. Subsequently, a new GSB (Guest State
Buffer) element for DPDES was added in Linux; the same has been missing
in TCG L0 implementation. Add support for DPDES register's APIv2 GSB
element and required handling in `spapr_nested.c`.
Currently, booting a KVM guest inside a QEMU TCG guest fails with the
following crash. The crash occurs while handling the GUEST_RUN_VCPU
hcall made in TCG L0. In the hcall handling path, map_and_getset_state()
calls getset_state(), which, in turn, calls guest_state_request_check()
to validate the GSR (Guest State Request) elements. During this process,
guest_state_request_check() iterates over the GSR elements and receives
a NULL return code from guest_state_element_type_find() for the type
variable corresponding to the DPDES register's elemetn ID (which was
unknown to TCG L0). Subsequently, getset_state() returns H_P3,
ultimately leading to the hcall failure and causing the KVM guest to
crash.
KVM: unknown exit, hardware reason ffffffffffffffea
[ ... KVM register dump ... ]
Fix this by adding the required support in TCG L0 implementation of
APIv2.
[1] https://lore.kernel.org/all/20240605113913.83715-1-gautam@linux.ibm.com/
Fixes: 4a575f9a0567 ("spapr: nested: Initialize the GSB elements lookup table.")
Suggested-by: Harsh Prateek Bora <harshpb@linux.ibm.com>
Signed-off-by: Amit Machhiwal <amachhiw@linux.ibm.com>
Reviewed-by: Harsh Prateek Bora <harshpb@linux.ibm.com>
Signed-off-by: Nicholas Piggin <npiggin@gmail.com>
| -rw-r--r-- | hw/ppc/spapr_nested.c | 1 | ||||
| -rw-r--r-- | include/hw/ppc/spapr_nested.h | 3 |
2 files changed, 3 insertions, 1 deletions
diff --git a/hw/ppc/spapr_nested.c b/hw/ppc/spapr_nested.c index c02785756c..1b41c8fb8b 100644 --- a/hw/ppc/spapr_nested.c +++ b/hw/ppc/spapr_nested.c @@ -982,6 +982,7 @@ struct guest_state_element_type guest_state_element_types[] = { GUEST_STATE_ELEMENT_ENV_DW(GSB_VCPU_SPR_FSCR, fscr), GUEST_STATE_ELEMENT_ENV_W(GSB_VCPU_SPR_PSPB, pspb), GUEST_STATE_ELEMENT_ENV_DW(GSB_VCPU_SPR_CTRL, ctrl), + GUEST_STATE_ELEMENT_ENV_DW(GSB_VCPU_SPR_DPDES, dpdes), GUEST_STATE_ELEMENT_ENV_W(GSB_VCPU_SPR_VRSAVE, vrsave), GUEST_STATE_ELEMENT_ENV_DW(GSB_VCPU_SPR_DAR, dar), GUEST_STATE_ELEMENT_ENV_W(GSB_VCPU_SPR_DSISR, dsisr), diff --git a/include/hw/ppc/spapr_nested.h b/include/hw/ppc/spapr_nested.h index 93ef14adcc..3b5cd993c2 100644 --- a/include/hw/ppc/spapr_nested.h +++ b/include/hw/ppc/spapr_nested.h @@ -99,7 +99,8 @@ #define GSB_VCPU_SPR_HASHKEYR 0x1050 #define GSB_VCPU_SPR_HASHPKEYR 0x1051 #define GSB_VCPU_SPR_CTRL 0x1052 - /* RESERVED 0x1053 - 0x1FFF */ +#define GSB_VCPU_SPR_DPDES 0x1053 + /* RESERVED 0x1054 - 0x1FFF */ #define GSB_VCPU_SPR_CR 0x2000 #define GSB_VCPU_SPR_PIDR 0x2001 #define GSB_VCPU_SPR_DSISR 0x2002 |