Messages in this thread | | | Subject | Re: [PATCH v2 03/13] powerpc/prom_init: Add the ESM call to prom_init | From | Alexey Kardashevskiy <> | Date | Thu, 18 Jul 2019 18:11:48 +1000 |
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On 13/07/2019 16:00, Thiago Jung Bauermann wrote: > From: Ram Pai <linuxram@us.ibm.com> > > Make the Enter-Secure-Mode (ESM) ultravisor call to switch the VM to secure > mode. Add "svm=" command line option to turn on switching to secure mode. > > Signed-off-by: Ram Pai <linuxram@us.ibm.com> > [ andmike: Generate an RTAS os-term hcall when the ESM ucall fails. ] > Signed-off-by: Michael Anderson <andmike@linux.ibm.com> > [ bauerman: Cleaned up the code a bit. ] > Signed-off-by: Thiago Jung Bauermann <bauerman@linux.ibm.com> > --- > .../admin-guide/kernel-parameters.txt | 5 + > arch/powerpc/include/asm/ultravisor-api.h | 1 + > arch/powerpc/kernel/prom_init.c | 99 +++++++++++++++++++ > 3 files changed, 105 insertions(+) > > diff --git a/Documentation/admin-guide/kernel-parameters.txt b/Documentation/admin-guide/kernel-parameters.txt > index 7b15abf7db21..c611891b5992 100644 > --- a/Documentation/admin-guide/kernel-parameters.txt > +++ b/Documentation/admin-guide/kernel-parameters.txt > @@ -4585,6 +4585,11 @@ > /sys/power/pm_test). Only available when CONFIG_PM_DEBUG > is set. Default value is 5. > > + svm= [PPC] > + Format: { on | off | y | n | 1 | 0 } > + This parameter controls use of the Protected > + Execution Facility on pSeries. > + > swapaccount=[0|1] > [KNL] Enable accounting of swap in memory resource > controller if no parameter or 1 is given or disable > diff --git a/arch/powerpc/include/asm/ultravisor-api.h b/arch/powerpc/include/asm/ultravisor-api.h > index c8180427fa01..fe9a0d8d7673 100644 > --- a/arch/powerpc/include/asm/ultravisor-api.h > +++ b/arch/powerpc/include/asm/ultravisor-api.h > @@ -19,6 +19,7 @@ > > /* opcodes */ > #define UV_WRITE_PATE 0xF104 > +#define UV_ESM 0xF110 > #define UV_RETURN 0xF11C > #define UV_REGISTER_MEM_SLOT 0xF120 > #define UV_UNREGISTER_MEM_SLOT 0xF124 > diff --git a/arch/powerpc/kernel/prom_init.c b/arch/powerpc/kernel/prom_init.c > index a3fb90bb5a39..6389a992451b 100644 > --- a/arch/powerpc/kernel/prom_init.c > +++ b/arch/powerpc/kernel/prom_init.c > @@ -44,6 +44,7 @@ > #include <asm/sections.h> > #include <asm/machdep.h> > #include <asm/asm-prototypes.h> > +#include <asm/ultravisor-api.h> > > #include <linux/linux_logo.h> > > @@ -175,6 +176,10 @@ static bool __prombss prom_radix_disable; > static bool __prombss prom_xive_disable; > #endif > > +#ifdef CONFIG_PPC_SVM > +static bool __prombss prom_svm_enable; > +#endif > + > struct platform_support { > bool hash_mmu; > bool radix_mmu; > @@ -816,6 +821,17 @@ static void __init early_cmdline_parse(void) > prom_debug("XIVE disabled from cmdline\n"); > } > #endif /* CONFIG_PPC_PSERIES */ > + > +#ifdef CONFIG_PPC_SVM > + opt = prom_strstr(prom_cmd_line, "svm="); > + if (opt) { > + bool val; > + > + opt += sizeof("svm=") - 1; > + if (!prom_strtobool(opt, &val)) > + prom_svm_enable = val; > + } > +#endif /* CONFIG_PPC_SVM */ > } > > #ifdef CONFIG_PPC_PSERIES > @@ -1716,6 +1732,43 @@ static void __init prom_close_stdin(void) > } > } > > +#ifdef CONFIG_PPC_SVM > +static int prom_rtas_hcall(uint64_t args) > +{ > + register uint64_t arg1 asm("r3") = H_RTAS; > + register uint64_t arg2 asm("r4") = args; > + > + asm volatile("sc 1\n" : "=r" (arg1) : > + "r" (arg1), > + "r" (arg2) :); > + return arg1; > +} > + > +static struct rtas_args __prombss os_term_args; > + > +static void __init prom_rtas_os_term(char *str) > +{ > + phandle rtas_node; > + __be32 val; > + u32 token; > + > + prom_debug("%s: start...\n", __func__); > + rtas_node = call_prom("finddevice", 1, 1, ADDR("/rtas")); > + prom_debug("rtas_node: %x\n", rtas_node); > + if (!PHANDLE_VALID(rtas_node)) > + return; > + > + val = 0; > + prom_getprop(rtas_node, "ibm,os-term", &val, sizeof(val)); > + token = be32_to_cpu(val); > + prom_debug("ibm,os-term: %x\n", token); > + if (token == 0) > + prom_panic("Could not get token for ibm,os-term\n"); > + os_term_args.token = cpu_to_be32(token); > + prom_rtas_hcall((uint64_t)&os_term_args); > +} > +#endif /* CONFIG_PPC_SVM */ > + > /* > * Allocate room for and instantiate RTAS > */ > @@ -3172,6 +3225,49 @@ static void unreloc_toc(void) > #endif > #endif > > +#ifdef CONFIG_PPC_SVM > +/* > + * Perform the Enter Secure Mode ultracall. > + */ > +static int enter_secure_mode(unsigned long kbase, unsigned long fdt) > +{ > + register uint64_t func asm("r3") = UV_ESM; > + register uint64_t arg1 asm("r4") = (uint64_t)kbase; > + register uint64_t arg2 asm("r5") = (uint64_t)fdt;
What does UV do with kbase and fdt precisely? Few words in the commit log will do.
> + > + asm volatile("sc 2\n" > + : "=r"(func) > + : "0"(func), "r"(arg1), "r"(arg2) > + :); > + > + return (int)func;
And why "func"? Is it "function"? Weird name. Thanks,
> +} > + > +/* > + * Call the Ultravisor to transfer us to secure memory if we have an ESM blob. > + */ > +static void setup_secure_guest(unsigned long kbase, unsigned long fdt) > +{ > + int ret; > + > + if (!prom_svm_enable) > + return; > + > + /* Switch to secure mode. */ > + prom_printf("Switching to secure mode.\n"); > + > + ret = enter_secure_mode(kbase, fdt); > + if (ret != U_SUCCESS) { > + prom_printf("Returned %d from switching to secure mode.\n", ret); > + prom_rtas_os_term("Switch to secure mode failed.\n"); > + } > +} > +#else > +static void setup_secure_guest(unsigned long kbase, unsigned long fdt) > +{ > +} > +#endif /* CONFIG_PPC_SVM */ > + > /* > * We enter here early on, when the Open Firmware prom is still > * handling exceptions and the MMU hash table for us. > @@ -3370,6 +3466,9 @@ unsigned long __init prom_init(unsigned long r3, unsigned long r4, > unreloc_toc(); > #endif > > + /* Move to secure memory if we're supposed to be secure guests. */ > + setup_secure_guest(kbase, hdr); > + > __start(hdr, kbase, 0, 0, 0, 0, 0); > > return 0; >
-- Alexey
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