Re: [V3 PATCH 08/16] powerpc/pseries/VAS: Implement allocate/modify/deallocate HCALLS
Excerpts from Haren Myneni's message of April 18, 2021 7:07 am:
>
> This patch adds the following HCALLs which are used to allocate,
> modify and deallocate VAS windows.
I don't like to be nitpicky about the language, but this is adding the
hcall wrappers. Implementing the hcall would be adding it to KVM.
Otherwise looks okay I think.
Reviewed-by: Nicholas Piggin
> H_ALLOCATE_VAS_WINDOW: Allocate VAS window
> H_DEALLOCATE_VAS_WINDOW: Close VAS window
> H_MODIFY_VAS_WINDOW: Setup window before using
>
> Also adds phyp call (H_QUERY_VAS_CAPABILITIES) to get all VAS
> capabilities that phyp provides.
"PAPR hcall to get VAS capabilities provided by the hypervisor"
Thanks,
Nick
>
> Signed-off-by: Haren Myneni
> ---
> arch/powerpc/platforms/pseries/vas.c | 217 +++
> 1 file changed, 217 insertions(+)
> create mode 100644 arch/powerpc/platforms/pseries/vas.c
>
> diff --git a/arch/powerpc/platforms/pseries/vas.c
> b/arch/powerpc/platforms/pseries/vas.c
> new file mode 100644
> index ..06960151477c
> --- /dev/null
> +++ b/arch/powerpc/platforms/pseries/vas.c
> @@ -0,0 +1,217 @@
> +// SPDX-License-Identifier: GPL-2.0-or-later
> +/*
> + * Copyright 2020-21 IBM Corp.
> + */
> +
> +#define pr_fmt(fmt) "vas: " fmt
> +
> +#include
> +#include
> +#include
> +#include
> +#include
> +#include
> +#include
> +#include
> +#include
> +#include
> +#include
> +#include
> +#include
> +#include
> +#include
> +#include "vas.h"
> +
> +#define VAS_INVALID_WIN_ADDRESS 0xul
> +#define VAS_DEFAULT_DOMAIN_ID 0xul
> +/* Authority Mask Register (AMR) value is not supported in */
> +/* linux implementation. So pass '0' to modify window HCALL */
> +#define VAS_AMR_VALUE 0
> +/* phyp allows one credit per window right now */
> +#define DEF_WIN_CREDS1
> +
> +static int64_t hcall_return_busy_check(int64_t rc)
> +{
> + /* Check if we are stalled for some time */
> + if (H_IS_LONG_BUSY(rc)) {
> + msleep(get_longbusy_msecs(rc));
> + rc = H_BUSY;
> + } else if (rc == H_BUSY) {
> + cond_resched();
> + }
> +
> + return rc;
> +}
> +
> +/*
> + * Allocate VAS window HCALL
> + */
> +static int plpar_vas_allocate_window(struct vas_window *win, u64 *domain,
> + u8 wintype, u16 credits)
> +{
> + long retbuf[PLPAR_HCALL9_BUFSIZE] = {0};
> + int64_t rc;
> +
> + do {
> + rc = plpar_hcall9(H_ALLOCATE_VAS_WINDOW, retbuf, wintype,
> + credits, domain[0], domain[1], domain[2],
> + domain[3], domain[4], domain[5]);
> +
> + rc = hcall_return_busy_check(rc);
> + } while (rc == H_BUSY);
> +
> + switch (rc) {
> + case H_SUCCESS:
> + win->winid = retbuf[0];
> + win->lpar.win_addr = retbuf[1];
> + win->lpar.complete_irq = retbuf[2];
> + win->lpar.fault_irq = retbuf[3];
> + if (win->lpar.win_addr == VAS_INVALID_WIN_ADDRESS) {
> + pr_err("HCALL(%x): COPY/PASTE is not supported\n",
> + H_ALLOCATE_VAS_WINDOW);
> + return -ENOTSUPP;
> + }
> + return 0;
> + case H_PARAMETER:
> + pr_err("HCALL(%x): Invalid window type (%u)\n",
> + H_ALLOCATE_VAS_WINDOW, wintype);
> + return -EINVAL;
> + case H_P2:
> + pr_err("HCALL(%x): Credits(%u) exceed maximum window credits\n",
> + H_ALLOCATE_VAS_WINDOW, credits);
> + return -EINVAL;
> + case H_COP_HW:
> + pr_err("HCALL(%x): User-mode COPY/PASTE is not supported\n",
> + H_ALLOCATE_VAS_WINDOW);
> + return -ENOTSUPP;
> + case H_RESOURCE:
> + pr_err("HCALL(%x): LPAR credit limit exceeds window limit\n",
> + H_ALLOCATE_VAS_WINDOW);
> + return -EPERM;
> + case H_CONSTRAINED:
> + pr_err("HCALL(%x): Credits (%u) are not available\n",
> + H_ALLOCATE_VAS_WINDOW, credits);
> + return -EPERM;
> + default:
> + pr_err("HCALL(%x): Unexpected error %lld\n",
> + H_ALLOCATE_VAS_WINDOW, rc);
> + return -EIO;
> + }
> +}
> +
> +/*
> + * Deallocate VAS window HCALL.
> + */
> +static int plpar_vas_deallocate_window(u64 winid)
> +{
> + int64_t rc;
> +
> + do {
> + rc = plpar_hcall_norets(H_DEALLOCATE_VAS_WINDOW, winid);
> +
> + rc = hcall_return_busy_check(rc);
> + } while (rc == H_BUSY);
> +
> + switch (rc) {
> + case H_SUCCESS:
> + return 0;
> + case H_PARAMETER:
> + pr_err("HCALL(%x): Invalid window ID %llu\n",
> + H_DEALLOCATE_VAS_WINDOW, winid);
> + return -EINVAL;
> + case H_STATE:
> +
[V3 PATCH 08/16] powerpc/pseries/VAS: Implement allocate/modify/deallocate HCALLS
This patch adds the following HCALLs which are used to allocate,
modify and deallocate VAS windows.
H_ALLOCATE_VAS_WINDOW: Allocate VAS window
H_DEALLOCATE_VAS_WINDOW: Close VAS window
H_MODIFY_VAS_WINDOW: Setup window before using
Also adds phyp call (H_QUERY_VAS_CAPABILITIES) to get all VAS
capabilities that phyp provides.
Signed-off-by: Haren Myneni
---
arch/powerpc/platforms/pseries/vas.c | 217 +++
1 file changed, 217 insertions(+)
create mode 100644 arch/powerpc/platforms/pseries/vas.c
diff --git a/arch/powerpc/platforms/pseries/vas.c
b/arch/powerpc/platforms/pseries/vas.c
new file mode 100644
index ..06960151477c
--- /dev/null
+++ b/arch/powerpc/platforms/pseries/vas.c
@@ -0,0 +1,217 @@
+// SPDX-License-Identifier: GPL-2.0-or-later
+/*
+ * Copyright 2020-21 IBM Corp.
+ */
+
+#define pr_fmt(fmt) "vas: " fmt
+
+#include
+#include
+#include
+#include
+#include
+#include
+#include
+#include
+#include
+#include
+#include
+#include
+#include
+#include
+#include
+#include "vas.h"
+
+#defineVAS_INVALID_WIN_ADDRESS 0xul
+#defineVAS_DEFAULT_DOMAIN_ID 0xul
+/* Authority Mask Register (AMR) value is not supported in */
+/* linux implementation. So pass '0' to modify window HCALL */
+#defineVAS_AMR_VALUE 0
+/* phyp allows one credit per window right now */
+#define DEF_WIN_CREDS 1
+
+static int64_t hcall_return_busy_check(int64_t rc)
+{
+ /* Check if we are stalled for some time */
+ if (H_IS_LONG_BUSY(rc)) {
+ msleep(get_longbusy_msecs(rc));
+ rc = H_BUSY;
+ } else if (rc == H_BUSY) {
+ cond_resched();
+ }
+
+ return rc;
+}
+
+/*
+ * Allocate VAS window HCALL
+ */
+static int plpar_vas_allocate_window(struct vas_window *win, u64 *domain,
+u8 wintype, u16 credits)
+{
+ long retbuf[PLPAR_HCALL9_BUFSIZE] = {0};
+ int64_t rc;
+
+ do {
+ rc = plpar_hcall9(H_ALLOCATE_VAS_WINDOW, retbuf, wintype,
+ credits, domain[0], domain[1], domain[2],
+ domain[3], domain[4], domain[5]);
+
+ rc = hcall_return_busy_check(rc);
+ } while (rc == H_BUSY);
+
+ switch (rc) {
+ case H_SUCCESS:
+ win->winid = retbuf[0];
+ win->lpar.win_addr = retbuf[1];
+ win->lpar.complete_irq = retbuf[2];
+ win->lpar.fault_irq = retbuf[3];
+ if (win->lpar.win_addr == VAS_INVALID_WIN_ADDRESS) {
+ pr_err("HCALL(%x): COPY/PASTE is not supported\n",
+ H_ALLOCATE_VAS_WINDOW);
+ return -ENOTSUPP;
+ }
+ return 0;
+ case H_PARAMETER:
+ pr_err("HCALL(%x): Invalid window type (%u)\n",
+ H_ALLOCATE_VAS_WINDOW, wintype);
+ return -EINVAL;
+ case H_P2:
+ pr_err("HCALL(%x): Credits(%u) exceed maximum window credits\n",
+ H_ALLOCATE_VAS_WINDOW, credits);
+ return -EINVAL;
+ case H_COP_HW:
+ pr_err("HCALL(%x): User-mode COPY/PASTE is not supported\n",
+ H_ALLOCATE_VAS_WINDOW);
+ return -ENOTSUPP;
+ case H_RESOURCE:
+ pr_err("HCALL(%x): LPAR credit limit exceeds window limit\n",
+ H_ALLOCATE_VAS_WINDOW);
+ return -EPERM;
+ case H_CONSTRAINED:
+ pr_err("HCALL(%x): Credits (%u) are not available\n",
+ H_ALLOCATE_VAS_WINDOW, credits);
+ return -EPERM;
+ default:
+ pr_err("HCALL(%x): Unexpected error %lld\n",
+ H_ALLOCATE_VAS_WINDOW, rc);
+ return -EIO;
+ }
+}
+
+/*
+ * Deallocate VAS window HCALL.
+ */
+static int plpar_vas_deallocate_window(u64 winid)
+{
+ int64_t rc;
+
+ do {
+ rc = plpar_hcall_norets(H_DEALLOCATE_VAS_WINDOW, winid);
+
+ rc = hcall_return_busy_check(rc);
+ } while (rc == H_BUSY);
+
+ switch (rc) {
+ case H_SUCCESS:
+ return 0;
+ case H_PARAMETER:
+ pr_err("HCALL(%x): Invalid window ID %llu\n",
+ H_DEALLOCATE_VAS_WINDOW, winid);
+ return -EINVAL;
+ case H_STATE:
+ pr_err("HCALL(%x): Window(%llu): Invalid page table entries\n",
+ H_DEALLOCATE_VAS_WINDOW, winid);
+ return -EPERM;
+ default:
+ pr_err("HCALL(%x): Unexpected error %lld for window(%llu)\n",
+ H_DEALLOCATE_VAS_WINDOW, rc, winid);
+ return -EIO;
+ }
+}
+
+/*
+ * Modify VAS window.
+ * After the window is opened with allocate window HCALL, configure it
+ * with flags and LPAR PID before using.
